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A story wrapped in myth and legend

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How did a tribe of wandering nomads

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engineer the Americas greatest empire

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in just 200 years

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they had to devise engineering systems which [br]were extraordinary for their age

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Their civilization rivaled Rome [br]in its sophistication

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The Aztecs had the best technology [br]that could be produced

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in the conditions of which they lived

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Acquaducts

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Palaces

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Pyramids

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and temples stood as a [br]tribute to their Gods.

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and a testament to the power of human kind

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The Aztecs crowning achievement [br]was a gleaming capital city

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That astonished European explorers called [br]the Venice of the new world

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The city spread out, [br]glittering against its canals

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and its lake be that with fine trees[br]and beautiful mansions

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their thirst for power and blood set [br]them on a course for destruction

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When it finally came

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their annihilation would be swifter

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and more complete than [br]the world had ever known

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1325 A.D.

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Central Mexico

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Near modern day Mexico City

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A young girl, just a teenager

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is celebrating her impending wedding

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She is the daughter of a tribal king

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and she is about to join a new tribe [br]that has been a guest of her kingdom

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That tribe is now known as the Aztecs

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As part of the ritual, five Aztec noblemen lead her [br]to an ancient temple for the ceremony

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But as she reached the top, [br]noblemen suddenly veer her away from the altar

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and onto a a slab of stone in front of the temple

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one used for sacrifice

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each man holds her limbs, [br]while a fifth lifts an obsidian knife high in the air

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with one searing move, he slashes it through [br]her chest, and extracts her still beating heart

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That evening, the king is invited to a ceremony to celebrate the marriage

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Instead, he finds a [br]priest performing a dance

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wearing the still glistening skin [br]of his daughter.

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As part of the ritual, the Aztecs [br]had flayed her to honor the God of fertility

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He saw this and he was [br]absolutely horrified at what he saw.

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His dear daughter

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He and his forces immediately [br]chased the Aztecs into the lake

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and onto this island [br]where they sought refuge

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The marshy island was an unwelcoming place

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yet it was from here that the Aztecs [br]would beat the odds against them

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And forge the most powerful [br]empire of the Americas

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Hi. I'm Peter Weller. When I think of the [br]Aztecs I think of an elegant people.

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with beautiful skin and flamboyant [br]headresses of many colors

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and I think of floating cities [br]and a terrific song by Neil Young.

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About Montezuma and Cortez.

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But I also think of knives of obsidian glass[br]ripping in the chest cavities

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and hands pulling out bleeding hearts [br]and holding them high

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Most of the Aztec sacrifices were performed in [br]the temple atop a stone pyramid like this one.

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The Aztecs felt that without [br]these offerings the sun would

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literally cease to rise and the universe would die.

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Now Aztec history is a fusion of fact and myth[br]

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but what we do know is that this murder as horrific as it was

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not only marked the beginning of the Aztec empire

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it also marked the location from where would rise.

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The island the Aztecs were banished to after [br]their disastrous sacrifice of the princess was in lake Textcoco.

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The largest of five interconnected lakes [br]covering a valley about 40 by 70 miles.

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Today, this once vast and open valley

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is teaming with what is modern day Mexico City.

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One of the largest cities in the world.

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But 700 years ago, the island was so [br]swampy no one had laid claim to it

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Now as they gazed on the lake.

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The Aztec leader Tenoch announced to his followers

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that he had seen an eagle, perched on [br]a cactus in the middle of the lake.

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A sign from the Gods that [br]they had found their new home.

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They would name their city Tenochtitlan.

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Life is tough for the Aztecs [br]in the early days of Tenochtitlan.

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But they have a vision.

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A vision of a powerful city

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Modeled on an ancient and legendary city just 25 miles away

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They called this city Teotihuacan

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or "City of the Gods."

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We know very little about Teotihuacan

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because all we have is the archaeological remains

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we don't have any writing we don't have any documentation

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that really flashed out what went on in this big city.

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It was in ruins even in Aztec times.[br]

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But they believed it to be the [br]stomping grounds of the Gods.

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And the literal birthplace of the sun itself.

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The place the Aztecs most revered in Teotihuacan

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was a pyramid that rose above the tree line.

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It was called "The Pyramid of the Sun".

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The massive Sun Pyramid contains [br]a million cubic yards of earth and stone

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with a base roughly the same [br]as the great pyramid of Giza in Egypt.

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The Aztecs believe Teotihuacan

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was laid out in the image of the cosmos

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created by their Gods.

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Now it was this image they would [br]attempt to replicate

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in the construction of their new city: [br]Tenochtitlan

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Taking on the challenge would be an Aztec leader named Acamoaoichtli.

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In 1376, he embarked on an ambitious plan to [br]engineer an advanced city at Tenochtitlan.

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But there was a problem.

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The swampy islands that they took over [br]needed a lot of work.

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When they started to build anything [br]it would begin to subside.

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There was simply no foundation on which to build.

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The Aztecs' solution would revolutionize the architecture of the Americas.

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They began by anchoring their buildings deep in the ground.

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Using a system of pylon made from wood.

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Workers cut stakes into thirty foot [br]lengths - three to four inches wide.

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These were driven into the soft ground [br]to make a foundation.

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The pylons were often surrounded [br]with volcanic stone to add strength.

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Masons and bricklayers could then build [br]walls on top of this base with confidence.

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They have found wooden pilings to hold the foundation of the buildings

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the fact that it didn't sink[br]or the fact that is didn't just topple

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I think that's a major feat of engineering

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Tenochtitlan was an island city

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but the lakes surrounding it were very shallow

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sometimes only seven feet deep

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The whole thing looked like a giant [br]metroplex floating on a pond.

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Originally, the only way to get from [br]this floating city the mainland was by boat

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But the Aztecs eventually devised

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a series of causeways sometimes 45 feet wide

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that would connect their floating city [br]to the mainland provinces.

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The causeways were supported [br]by strong wooden pilings

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the same pilings that supported [br]their temples and other buildings

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thousands of these pilings had to be [br]driven deep into the lake bed

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and this presented a logistical challenge

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that can only be met by a strong skilled labor force

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and the best of Mesoamerica's engineers.

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To build a causeway, two lines of steaks were laid out.

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Then the space between them was filled [br]with stones and earth

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until it reached several feet above the water level.

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This allowed the road to support enormous weight.

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These causeways were built very straight.

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They were very wide with [br]bridges that would open up.

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That connected the city to the north to the west

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and to the south.

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The roads enabled the Aztecs to transport [br]larger heavier materials for building.

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But this presented a new challenge

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there were no beasts of burden in Mesoamerica so

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everything had to be done with humans

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no carts, no wheel

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Small loads would be carried on the back [br]with a rope hung from the forehead.

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Large items like stone blocks or [br]sculptures for a temple[br]

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would be dragged by huge numbers of men

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pulling ropes, possibly using logs as rollers

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Legend has it one stone bound for a temple[br]required the force of 50 thousand men

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To drag it from the mountains on the [br]mainland, across the causeway and into the city

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The causeways would also present the Aztecs [br]with a new way to get fresh water to Tenochtitlan.

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In the past, the Aztecs had transported [br]water in canoes from the shore.

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But a huge boom in the city's population [br]meant they needed a higher tech solution

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to keep up with demand.

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They wanted to use water from [br]the springs on the mainland.

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And so they wanted to build an acquaduct.

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But the springs were under control of the [br]dominant tribe in the region:

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the ruthless Tapaneks.

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The Tapaneks were the controllers or [br]the dominators of all the valley.

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They had a very strong empire.

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So they were the lords of the valley.

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So the Aztecs were tributary subjects to them.

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As the Aztec population grew, [br]tensions with the Tapaneks began to simmer.

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Now the Aztecs decided to issue an ultimatum

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that could change the balance of [br]power in the region.

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The people of Tenochtitlan not only demanded [br]that the Tapaneks give them the water

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but also demanded that they help [br]construct the acquaduct.

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The Tapaneks' answer was swift and brutal.

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The Tapanek king Makstala sent assassins [br]who murdered the reigning Aztec leader in cold blood.

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This was the final straw.

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After decades of domination, the Aztecs [br]would finally make their move[br]

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and wage war against their ruthless overlords.

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And they would launch a series of [br]wildly ambitious building projects

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around their growing island city

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that would earn them a reputation [br]as the greatest engineers of the Americas.

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It is 1428, and the Aztecs have [br]declared war on their overlords

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a tribe calles the Tapaneks.

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But to defeat the Tapaneks, they would need a little help from their neighbors.

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The Aztecs approached the nearby [br]city state of Texcoco.

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There, a decisive leader was on the rise.

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His name was Nezahualcóyotl

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and his domineering leadership would [br]be instrumental in forging the Aztec empire.

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With Nezahualcóyotl at their side, the [br]Aztec underdogs woud go for the jugular.

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They launched an all-out attack on the Tapanek capital.

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After a siege of more than 100 days,

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they broke through Tapanek defenses and[br]slaughtered their oppressors.

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After capturing the Tapanek king, Makstala, [br]king Nezahualcóyotl personally cut out his heart

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and sprinkled his blood into the waters of lake Texcoco.

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Suddenly, the tables had turned.

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That is the exact moment of the [br]beginning of the empire.

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And the Aztecs became the leaders of [br]the valley of Mexico.

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After conquering the valley of Mexico,

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the Aztecs could now turn their attention [br]to bringing clean water to their growing city.

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Remarkably, the Aztecs would [br]independently design and build

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something a few world empires would master: [br]

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the aquaduct.

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The aqueduct actually had two channels [br]each about five feet high and three feet wide.

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One would be cleaned and maintained [br]while the other was being used

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so the water flow was never interrupted.

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The twin tube aqueduct ran for [br]three miles from the mainland

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to the center of the island city.

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In town, water streamed into public [br]fountains and reservoirs.

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and was distributed to the public in [br]large clay jars or by canoe.

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In comparison to the Europeans, the Aztecs[br]were a very clean people.

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We know that the Aztec emperor bathed twice a day.

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So, in terms of higiene, the Aztec people [br]was much more advanced than the Europens.

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While the Aztec nobles were bathing in [br]luxury, at this time in Europe, plague

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caused by unsanitary conditions was killing millions.

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King Nezahualcóyotl's own bath was [br]one of the most unique in the Americas.

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In was fed by a sophisticated aqueduct system [br]that also brought running water to his palace grounds.

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Behind me is the hill of Texcotzingo, and on this hill[br]Nezahualcóyotl built a fantastic treasure palace.

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and around this palace a virtual [br]botanical garden, filled with all

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the exotic flowers of Mesoamerica.

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Nezahualcóyotl brought water [br]from the Sierra Nevada mountains

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all the way down to here into this hill, [br]to his palace just to water his plants.

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To install an aqueduct there,

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Nezahualcóyotl had to fill a huge gorge [br]between Texcotzingo and the next will.

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As the water arrived at the first hill,[br]it gathered in small pools

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build to control the speed of the [br]flow before it reached the aqueduct.

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After crossing the aqueduct, the water [br]ran in a circuit around Texcotzingo hill

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Spilling off over the sides in [br]rock-cut waterfalls

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to water the gardens.

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it ended up in a nearly perfectly round rock cut pool called the king's bath