Egypt's Lost Wonders (Full Episode) | Drain the Oceans

NARRATOR: The mysteries of ancient Egypt, and its hidden secrets. MATTHEW: These tombs represent the technology of resurrection. STEVEN: They created monuments that make the mind boggle.

NARRATOR: Some of their greatest achievements, lost beneath the sand and water of the Nile valley. . .

until now. Imagine if we could empty oceans, or drain the desert, and reveal the secrets beneath. Now we can.

Using the latest imaging technology to pierce sea and sand and turn accurate data into 3D images. Can scientists solve the mystery of Alexandria's Lighthouse and recreate one of the ancient wonders of the World? Why did a Pharaoh build 15 mega-forts when none of them saw a major battle?

LAUREL: This is a forgotten age in Egyptian history because we have lost access to these monuments. NARRATOR: And what does a fleet of boats, buried six miles from the Nile, reveal about Egypt's original 'Valley of the Kings'? ♪ ♪ NARRATOR: Ancient Egypt.

. . One of the greatest civilizations on Earth.

It lasts for 3,000 years. Its people develop a remarkable written language using pictures and symbols. They worship strange gods.

And they build two of the seven wonders of the ancient world. The first, the great pyramids of Giza. -The ancients determined the seven wonders because they met certain criteria.

It is the ingenuity of the design, but it had to be built on a super colossal, over the top scale. NARRATOR: The Egyptians' second ancient wonder is the lighthouse of Alexandria. Known as the Pharos, it is built on a grand scale like the other wonders: The Hanging Gardens of Babylon and the Colossus of Rhodes.

Of the seven wonders, only the pyramids now survive. But as the waters of the Nile Delta drain away, can the architectural marvel of the Pharos be brought back to life from the seas around Alexandria Harbor? And recreated accurately for the first time a sight that once dazzled the world.

-The Pharos ranked as one of the seven wonders of the ancient world because it was something that had never been seen before. Some people say um the beacon could be seen 30 miles out to sea. NARRATOR: Alexandria's lighthouse is a technological and architectural masterpiece.

Built in the third century BC, it's the crowning glory of a new capital city, founded by the conqueror of Ancient Egypt: Alexander the Great. -Alexandria was the be-all and end-all. Um you might think of the Champs Elysee in Paris or Times Square in New York.

Alexandria was all of those things and more. Um it was the most beautiful city that the world had ever seen. NARRATOR: Egypt's new rulers want the Pharos to send a big and simple message.

EMAD: They wanted to show how powerful is the city. So you'd need a sign, a big huge banner that says welcome to Alexandria. The Pharos was created mainly as a landmark.

NARRATOR: But once Egypt's power has faded, Alexandria's famous lighthouse falls into disrepair. The land beneath it slowly subsides into the sea, and in the 14th century it finally collapses after it's struck by an earthquake. The Pharos is thought to be lost here, beneath 23 feet of water, at the entrance of Alexandria harbor.

Now a French team of archaeologists is trying to rediscover its true magnificence. Using the latest undersea imaging technology, they're scouring the seabed for clues. Their aim is to digitally rebuild this lost Ancient Wonder of the World, for the first time.

Leading the investigation is architect and archaeologist Isabelle Hairy. She's been searching for the truth about Alexandria's lighthouse for more than 20 years. ISABELLE: It's always very rewarding to work on one of the seven wonders of the ancient world.

I'd be lying if I said otherwise. NARRATOR: Isabelle's team is working in one of the largest underwater archaeological sites in the world. They investigate some mysterious granite blocks.

These remarkable remains are clearly man-made. Could they be from the missing ancient wonder? Isabelle's task is to unlock the true dimensions and design of the Pharos.

But her job is made harder by the wildly conflicting accounts of what it actually looked lik. -We came across these quite extraordinary images of the lighthouse. NARRATOR: Different impressions from past travelers and artists shroud the true appearance of the lighthouse in mystery.

-It's depicted here as the Tower of Babylon. Here a very classical building with floors one above the other, with doors opening into mysterious rooms. NARRATOR: Over time, ideas about the Pharos grew even more fantastic.

-One of the authors was speaking about the Pharos being so tall and so extensively high, if a stone was thrown from the top of the lighthouse it would reach land in 2 days or 3 days. It's not true but it is saying something about how those people saw the lighthouse. NARRATOR: Where does the truth lie?

Will the underwater granite blocks provide answers? To find out, Isabelle's team uses a technique called photogrammetry capturing thousands of detailed images across the enormous site. -This is closer view here on the map.

This is block 1003. -Do you think we can go further, we can go more on the North? NARRATOR: After 28 weeks of diving and with 50,000 photographs, Isabelle has the data she needs to finally unlock the secrets of the Pharos.

Combining this unique data with cutting edge computer graphics means that for the first time, the waters around Alexandria harbor can be drained away. As the Mediterranean begins to empty, surprising shapes come into view. Nearly 3,000 granite blocks scattered across three acres of the seabed.

These are not natural rock formations, but clearly the work of human hands. Statue bases, chunks of pillars. All from a building of monumental proportions.

The drowned ruins of a genuine ancient wonder, The Pharos lighthouse. Brought back into the light of day for the first time in 600 years. Already Isabelle's work has delivered one revelation.

Some of the blocks from the drained landscape are a crucial clue to the shape of the Pharos. -Drining the site has enabled us to see the lighthouse. We've even found blocks that might have formed the corner stones, but no blocks found underwater indicated the walls sloped.

The walls were straight. NARRATOR: This is the first physical proof of the lighthouse's design. A huge advance on all previous knowledge.

But piecing together the rest of the underwater jigsaw remains an enormous challenge. -What we have here is a puzzle, basically it's a 3000 pieces puzzle that you have to try to fit things together. Will it fit or will it not fit?

NARRATOR: And what's more, some crucial parts of the puzzle are missing, taken to museums by previous excavations. But one important piece lies nearby, abandoned on the quayside. -This was probably the greatest discovery, found on the site.

NARRATOR: But what is it? -So, here we have a side part of a door frame. We know because this is the place where the door would have been fixed.

NARRATOR: This groove is carefully carved as the frame for a gigantic door. And incredibly, Isabelle can match the frame's distinctive shape to other stones lying underwater. They must all be pieces from the same doorway.

-By joining this huge fragment almost 12 meters long together with all the other fragments, we can reconstruct a door. It's one of the most important pieces of the site. NARRATOR: Now, for the first time, it's possible to recreate the door to the Pharos.

The entrance to a Wonder of the Ancient World. -So now we are able to connect it with the lintels. The upright, ah perfect.

That's great. NARRATOR: The drained site reveals the lost fragments of the giant doorframe. Using the scanned images of the seabed, its huge blocks come into view.

Computer graphic technology reverses the centuries. The pieces of the doorframe fit together perfectly. And within the granite frame a vast wooden door was once fastened.

All of it reaching 41 feet high and weighing more than 200 tons! The Pharos entrance is restored in the place where it fell. A monumental piece of architecture dwarfing anyone who enters.

For the first time, a part of Alexandria's lighthouse is accurately reconstructed. But what does the rest of the Pharos look like? And does it truly deserve its title as a wonder of the Ancient world?

NARRATOR: Archaeologist Isabelle Hairy continues to search for the truth about the Pharos lighthouse. Historical reports are conflicting. But most agree on one thing, that the Pharos has three distinct levels, each shaped differently.

Isabelle heads to the place where the lighthouse is thought to have stood. Now the site of another grand building, Qaitbay Fort. Built in 1477, just 42 years after the ruins of the Pharos are last reported visible.

Inside, an intriguing clue. Isabelle believes that its mosque is a small-scale replica of the Pharos. ISABELLE: You really get the impression of being in the ancient lighthouse even though the scale isn't the same, but there's this sense of space, still present, which we can feel all around us.

NARRATOR: The main tower is square. Above, it's topped by an octagonal and then a circular section. Isabelle's theory is that the Mosque's architects intended this to be a tribute to Alexandria's most famous building.

So is the Pharos shaped like this? To solve this mystery, Isabelle needs to compare her 3D data with historical reports and discover the true scale of the Pharos. Some dimensions were recorded by Medieval travelers.

In 1166, Al-Balawi from Spain penned a precise description of the lighthouse, reporting it to be 300 cubits high. Over a century later, Moroccan scholar Ibn Battuta recorded the thickness of the Pharos walls as 10 spans. The problem is these units are lost to history.

Until now. The breakthrough comes from the Pharos' reconstructed door frame. Its outside edge reveals the exact thickness of the lighthouse's exterior wall.

The dimension also recorded by Ibn Battuta, centuries earlier. His 10 'spans' is equal to six feet ten inches. -It's a discovery that's incredibly rewarding.

We are now able to decipher the texts of Ibn Battuta, and the texts of Al-Balawi. NARRATOR: It's a huge leap forward. Converting medieval units into accurate modern measurement unlocks the true scale of the Pharos for the first time.

Combining all the underwater evidence with Al-Balawi's descriptions solves a centuries old puzzle. Revealing three towers that match the design of the mosque, making it possible to reconstruct a lost ancient wonder in exact detail. Statues from Alexandria's museums return to their original homes.

Believed to be clad in limestone, the Pharos reaches almost 330 feet into the sky. The size of a 32 story building, it's one of the tallest structures in the Ancient World. And all of it is thought to be crowned by a wonder of ancient technology, fires and iron mirrors reflecting the light and the glory of Egypt to the world beyond.

-It could have looked like the first skyscrapers built in Chicago at the end of the 19th century. It's really a fabulous structure. STEVEN: The ancients determined the seven wonders because they met certain criterias, and so the Pharos satisfies all of those ancient criteria of innovative design, that was actually built, that was actually towering.

NARRATOR: Most importantly the Pharos marks the gateway to Ancient Egypt and the mighty river Nile. More than 4,000 miles long, the Nile is the longest river in the world. JON: The Nile was absolutely central to Ancient Egypt.

It was the seasonal flood that brought this rich, black mineral mud and deposited it on the fields and made it fertile. It was actually that that drove Ancient Egyptian civilization. Without the Nile it wouldn't have happened.

NARRATOR: Six and a half thousand years ago farmers make these riverbanks their home, and a civilization is born. Six miles west of the Nile, draining, not water, but sand, reveals an ancient mystery known as the Abydos boats. -It was completely unexpected to find a phantom flotilla in the middle of nowhere.

NARRATOR: Why is there a fleet of boats beneath the sands of the Egyptian desert? Egyptologist Matthew Adams has excavated Abydos' mysterious boats for 30 years. MATTHEW: One would never know by looking at this flat patch of desert that underneath the sand is one of the most remarkable discoveries ever made in Egyptian archaeology.

NARRATOR: The boats he excavated have been reburied in the sand to help preserve them for the future. Before then, they'd been lying undisturbed for 5000 years. -Was this the result of some great flood of the river that they sailed here and were left stranded?

It's a very strange setting for a group of boats like this. -You would think perhaps it was a dried up quay or it was perhaps an area where the Nile once ran. NARRATOR: Throughout its history the Nile has shifted course.

But it never ran here. Abydos lies on a desert plateau out of the river's reach. So if the Nile didn't bring these boats here, what did?

To find out, Matthew's team surveys the location of the boats and the surrounding terrain. Accurate satellite mapping can reveal the extraordinary world beneath. Combining this data with the latest computer imaging allows the Egyptian desert to be drained of sand, grain by grain to solve an ancient mystery.

The desert begins to reveal its secrets. Not one boat, Not two, but 14. The surviving fragments of timber reveal they are 60 feet long.

All carefully lined up in parallel. It's the oldest buried fleet ever discovered. But who does it belong to?

Reconstructing the boats immediately reveals a clue. These are not simple dugout canoes nor are they boats made from reeds. They're substantial rowing vessels, with space for up to 30 oarsmen.

More revealing still is the way they're made from carefully crafted wooden planks all stitched together with rope. -These are they earliest plank boats that we have in this area, as status symbols they're important. NARRATOR: 5,000 years ago, this is cutting edge nautical technology.

-It's almost like taking a sports car today and burying it in the desert somewhere. NARRATOR: And in Ancient Egypt only one person can afford such an immense investment. -Only the king could expend resources at this level and was in a position to dispose of a fleet a royal fleet in this way.

NARRATOR: The 14 boats belong to a Pharaoh. But what are they doing abandoned in the desert? ♪ ♪ NARRATOR: To unravel the mystery of the Abydos Boats Egyptologist Matthew Adams hunts for clues above the sand.

Next to the buried fleet stands a huge mud brick ruin. Here Matthew finds evidence of an ancient belief system that could help explain this desert secret. MATTHEW: These massive walls created a kind of religious space, where one of Egypt's first kings was worshipped.

NARRATOR: Excavations here uncover ancient pots that once contained food and beer. -Ceremonies took place in here, focused on this king as a kind of divine figure. Somehow these boats are part of this religious expression and they're connected to the activities of these early kings.

NARRATOR: This enclosure is built for the Ancient Egyptians to worship their pharaoh as a god, as long ago as 2700 BC, 200 years before the great pyramids. And more than a thousand before Tutankhamun. But what is the connection between this early worship of a Pharaoh and the mystery fleet?

A closer examination of the drained boats reveals the answer. Surrounding each one is a curious mud-brick casing. The brick walls follow the curve of the boats, completely covering them from stern to bow.

Returning them to their original state reveals more. Built on the desert surface each brick 'case' completely encloses a single boat. And all are covered in a layer of white plaster.

Creating 14 boat graves. -When the boats were newly put in place, you wouldn't have seen the boats themselves, the wooden boat hulls, you would've seen these brick grave structures. NARRATOR: The boat tombs are designed to be highly visible.

JON: This plaster would have caught the light of the sun when they were first built. -Seen from a distance they would have been glowing in the desert. NARRATOR: And all to honor a Pharaoh.

-Like the offerings that were delivered for his benefit inside the monument, bread and beer and wine, the boats must represent a kind of offering to him. NARRATOR: What beliefs inspire the Ancient Egyptians to create all of this, and to place it so far away from the Nile, where they actually live? Just a mile away, there's another clue.

This strange subterranean architecture is built around the same time the boats are left in the desert. It's the last resting place of one of Egypt's earliest Pharaohs. -This is the spot where the king ended his life in this world and made the transition from here to the other world, where he would have his eternal life.

NARRATOR: The tomb is designed to ensure the dead Pharaoh passes into another realm known as the afterlife provided with all the essential possessions he needs: food, drink, even his servants, ritually killed to serve their master beyond the grave. -These are the chambers in which the courtiers and retainers who were sacrificed to accompany the king into the next world were buried. And the, whole assemblage, the king in his burial chamber, his funerary enclosure and the boats that were buried next to it, the whole assemblage is being translated from this world to the next to be available to him there.

NARRATOR: Just like the dead courtiers, the Royal fleet is there to serve the Pharaoh in the afterlife. So he can navigate the celestial Nile for all eternity. The Abydos boats mark the beginning of a belief in the afterlife that eventually creates the pyramids and the Valley of the Kings.

And more signs of that connection still lie hidden beneath the sand. So Matthew's team carries out what's called a 'magnetometry' survey. It detects variations in the soil's magnetic field to reveal structures underground, not seen for thousands of years.

ALEX: We walk over it every day, but what we don't see is all of this. NARRATOR: The data reveal the origin of Egypt's obsession with the afterlife. -All of these darks lines that we can see here, these are all walls from buried structures.

Big ones, small ones. We can identify these as tombs, which makes this a gigantic vast desert cemetery. NARRATOR: It's an astonishing discovery.

Drining the sand from the rest of the plateau exposes Ancient Egypt's oldest Royal burial ground. A landscape designed for one purpose: Resurrection. Combining data from the surveys and excavations with computer generated imagery reveals the Pharaoh's tomb from below.

But now, drained of sand, another nine huge underground complexes appear. At least ten royal tombs fill the valley floor. Built more than a thousand years before the Valley of the Kings, this is Ancient Egypt's original city of the dead.

And nearby, more ritual enclosures where Pharaohs are worshipped and the tombs of the royal boats. It's the landscape at Abydos that reveals the ultimate reason why all these structures are built so far from the Nile. It all sits at the entrance of a narrow gorge.

The gateway to the afterlife. -I think it's very likely that the Ancient Egyptians viewed this canyon as the road that led to the land of the dead. The sun set in the west, the west was where the dead were, that was the other world and this canyon leads directly in that direction.

NARRATOR: The people who build this sacred site believe that everything placed here is destined to join the Pharaoh in the afterlife. -Abydos is vital because it's the first area where we see Pharaohs being deposited into graves and treated in this specialized way with gifts for the afterlife and that carries on for millennia. NARRATOR: The tradition that began with the Abydos boats can be seen 200 years later at the pyramid tomb of King Khufu.

His mummified body accompanied by a ceremonial boat. Around 1,200 years later the boy King, Tutankhamun is entombed with 35 model boats. Ensuring that in the afterlife each Pharaoh can navigate the all-important Nile.

The Ancient Egyptians are master builders. Their spectacular tombs and temples populate more than 900 miles of the Nile Valley. But draining the waters behind the Aswan dam reveals something very different.

One of the largest state building projects after the pyramids, a series of 15 massive forts. LAUREL: When we think about ancient Egypt we think of a peaceful society we think about temples and tombs and we don't think about the military. NARRATOR: And the forts that the Egyptian military build here are immense, as technologically advanced as the castles of Medieval Europe that weren't built for another 3000 years.

And yet there is little evidence that any of them saw a battle. Can draining the Nile reveal the true purpose of the mystery forts? NARRATOR: For more than 50 years Ancient Egypt's forts are lost beneath the waters of Lake Nasser.

. . their exact purpose, a mystery to archaeologists.

Viewing them on the lakebed is impossible. Sediment makes the waters impenetrable to cameras. And diving here can be fatal.

But there is one clue. Archaeologist Laurel Bestock is travelling to its remote location, deep in Sudan, near the Southern end of Lake Nasser. Fort Uronarti, one of the last surviving strongpoints from Ancient Egypt's southern frontier.

Laurel is fascinated by these forgotten forts and has been excavating Uronarti for six years. -I had thought that I would never be able to see, let alone study personally, such a place. That I could potentially come here was a really a personally profound and a career changing discovery.

NARRATOR: Laurel is searching for evidence to help her reveal the secrets of the forts that lie beneath the waters of Lake Nasser. Fort Uronarti itself is built around 1850BC, during an era known as the Middle Kingdom. It stands 200 miles south of Ancient Egyptian territory in what was once no man's land.

-This represents the edge of the known world to the Egyptians. Egypt is behind me up the Nile, that's the familiar world, the world where the Egyptians felt at home, they knew how to behave in this place. It's a culture and a landscape together.

Out there is the rest of ancient Africa, and that's very much a, a place that the Egyptians conceive of as terrifying, it's where they view the people and even the landscape itself as a threat to their order. NARRATOR: Beyond Egypt lies the land of Nubia. .

. and the kingdom of the Kushites. Their fearsome warriors raid Egypt from the south.

So the Pharaohs need to secure their territory. Clues to how they do it can be found at Uronarti. -Uronarti is really built for defense.

It's hard to imagine a space that would be more difficult to attack and you come up this steep hill and you're met with this massive fortified gateway. We're standing in between the remains of what was two towers, even thicker than the walls of Uronarti itself. You can see how massive the brickwork is here.

It's even reinforced you can see there are, are the remains of beams coming through the walls that would have acted like rebar in reinforced concrete here. NARRATOR: Fort Uronarti is a powerful deterrent to the hostile Kushites. But it's barely a fraction of the military might Ancient Egypt is about to unleash on its enemy.

Most of that military machine now lies beneath Lake Nasser, one of the largest reservoirs in the world. The forts are lost forever when Egypt builds the Aswan High Dam in the 1960s, to produce hydroelectric power and control irrigation. The rising waters threaten some of Egypt's greatest monuments.

So one of the world's largest archaeological salvage operations begins, involving 15 countries and more than $72 million. Monuments that can't be moved are excavated and recorded including Ancient Egypt's lost fortresses. Today, one of the most complete sets of archaeological reports from that time is kept at the Egypt Exploration Society.

CEDRIC: First of all you see how huge these forts were. NARRATOR: And reveals some tantalizing clues. CHRIS: And yet, since this was taken all of this is gone?

-Completely flooded, yes unfortunately. -Incredible -So this is why we're all so thankful to the mission that has excavated and recorded all these forts. NARRATOR: Today investigators are analyzing the evidence to discover why the Egyptians need as many as 15 forts.

Using this data and the latest computer graphic technology it's possible to drain the waters from Lake Nasser. 44 trillion gallons of water are unleashed into the Nile slowly revealing a world that's 4000 years old. Travelling south beyond Ancient Egypt, Fort Iken appears.

Then Fort Askut. Furthest south two more, Fort Kumma and Semna. Altogether a total of 15 forts.

Spanning 200 miles, it's the longest fortified frontier in the world, along this strategically important stretch of the Nile. STEVEN: Because the Nile river was the principal thoroughfare up, the forts were arranged north to south, stopping any invasion from the south into the north. NARRATOR: The wall of forts transforms the Nile into a formidable barrier against the Kushites.

But why do the Ancient Egyptians need to dominate territory so far beyond their heartlands? A clue comes from a fort inscription. It reveals that much of the frontier is created to satisfy one Pharaoh's military ambition.

PHARAOH: I have made my boundary further south than my fathers. NARRATOR: And how he boasts about crushing the Kushite enemy. PHARAOH: They are not people one respects.

They are wretches. I have captured their women, gone to their wells, killed their cattle, cut down their grain, set fire to it. -They definitely claimed this territory for their own by building these fortresses and said 'this is Egypt's now'.

JON: These forts are representing a sort of consolidation of power of the Pharaoh. NARRATOR: But why does Ancient Egypt need so many forts constructed on such a massive scale? Could they have been built to protect something even more valuable than a Pharaoh's power?

NARRATOR: When Egypt's Aswan Dam is built in the 1960s the largest fort to disappear beneath Lake Nasser is Fort Buhen. Hidden inside it is evidence of Ancient Egypt's military secrets. Drining the water from Lake Nasser, reveals traces of Fort Buhen, not seen for more than 50 years.

By combining the archaeological data with 3D computer graphics Fort Buhen is reconstructed. Revealing the nerve center of Ancient Egypt's frontier for the first time. And it's colossal!

Buhen's vast footprint covers an area 20 times larger than Fort Uronarti. Its perimeter wall, almost a mile circuit. The 36 foot high walls dominate the riverfront.

This is Fort Buhen in all its original glory. And everything about it is designed to intimidate. LAUREL: It really shows the state power.

It puts it outside so it's not just a symbol to the Egyptians, it's a symbol to other people. JON: These forts were clearly about military power. They were about domination.

-One of the purposes of this monument is to be imposing. NARRATOR: The monumental scale of Buhen is designed to terrify the Kushite enemy and proudly display military architecture so advanced, that it makes any raid on it, futile. STEVEN: What's unbelievable is if I told you, that all of the features that you find in mediaeval European forts were already in place in these mud brick forts 2000 to 1800 BC in Egypt, you would say no, you're wrong.

NARRATOR: 3,000 years before the famous castles of Europe are built, Fort Buhen has a dry moat, a fortified gateway, defensive battlements and sophisticated arrow loops with a firing arc of 180 degrees. -Basically, everything that you come to love about a mediaeval fort is already there in the Middle Kingdom forts in Egypt. NARRATOR: It seems the intimidating power of the forts achieves its aim.

Archaeological investigations here uncover almost no evidence of fighting. Is this lack of violence, a clue that the Nile frontier has another, entirely different purpose? Evidence lies deep inside Fort Buhen.

Archaeologists believe that within the citadel lies a complex of enormous silos for storing precious grain. -The size of those granaries means that they could hold way more food than is necessary for the number of people who would have lived at Buhen and that's an important clue for us in terms of the economic activity that's going on. NARRATOR: Egypt is trading grain for gold.

The forts not only dominate Ancient Egypt's southern neighbors, they also guard the trade routes from the gold mines of Nubia. To the Egyptians, gold is all important. And Nubia is the main source.

The Pharaohs and their wealthiest subjects wear gold and cover their coffins with it as the ultimate symbol of power. -The building of the fortresses was an attempt to impose a trading monopoly on gold coming up from the south and to make sure that this is all happening through the Egyptian state. NARRATOR: No one can pass through this 200-mile stretch of territory undetected.

Filled with soldiers, the forts form an effective surveillance system designed to trap thieves, smugglers and raiders. By ensuring all trade happens inside the forts Egypt secures the best of the deals for itself. These are the Fort Knoxes of the Ancient Egyptian world, trading gold and defending it from attack.

Inside both Fort Uronarti and Fort Buhen there are clues to the scale of that operation. -This space was a barracks house, and this is a pattern we see repeated throughout the fortress. NARRATOR: Buhen reveals many similar barracks, divided into larger communal areas and smaller rooms that archaeologists identify as sleeping quarters.

-We can calculate how many people might have been able to sleep in the fortress at any given time. From the space that's here it's a fairly decent space but if you think of soldiers lying close next to one another this could pack ten people in this room with no problem and if you think I'm relatively tall for an ancient Egyptian but if I lie here with my companions next to me you can get 10 of us in this room with no problem. NARRATOR: Scaling up, it's estimated that Uronarti could house 400 soldiers.

And Buhen thousands more. -So you're looking at a multi-functional, multi-purpose facility that was vibrant and alive and was like a little city contained within itself. NARRATOR: At full capacity the whole fortress system could be packed with 10,000 soldiers, scribes and officials.

Operating such an advanced frontier in far-flung lands is the pinnacle of Ancient Egypt's military achievement. An organizational feat on a scale that's similar to the building of the great pyramids. -You can see how this architecture enables this activity and really this bustling city on the edge of the Nile here at the edge of the world.

NARRATOR: Ancient Egypt's forts protect its unique civilization from invasion and enable it to control the gold trade. Bringing glorification to its Pharaohs for the centuries to come. By the 1st Century BC the Ancient Egyptians are no more.

But the mysteries they leave behind beneath the Nile Valley are a permanent reminder of their extraordinary culture. The legacy of Ancient Egypt lives on. Its architectural treasures, remarkable beliefs, formidable state power, and its golden voyages between the worlds of the living and the dead.

Captioned by Cotter Captioning Services.