More than 100 years before Columbus arrives in the 'New World'... The Aztecs reign over Mesoamerica as the last great culture before the Spanish conquest.
As they venture south, a group of warriors makes a stunning discovery.
Giant pyramids, the remains of an enormous ancient city - completely abandoned - a ghost town.
The Aztecs are certain: Only the gods could have built this place.
They call it 'Teotihuacan,' The City of the Gods.
Nearly 700 years later, the Aztecs' question remains unanswered: Who built this magnificent city?
One man believes he has found the answer: Mexican archaeologist Sergio Gomez Chavez.
I have been working for 34 years in Teotihuacan and am about to uncover the mystery of the City of the Gods.
The city is more than two thousand years old.
The Pyramid of the Moon lies at the northern end of the main avenue, the Street of the Dead.
Towering nearby is the Pyramid of the Sun, the third-largest pyramid in the world.
Their builders left no written records, only the ruins of their civilization.
It's easy to imagine that the Aztecs themselves believed that this city was created by the gods.