Tenochtitlan

Tenochtitlan was the capital of the Aztec civilization, located in Mexico.

In 1520, Giovanni Borgia, an Assassin tasked with obtaining a Crystal Skull, secretly travelled with Hernán Cortés to Mexico. While the Spanish came in peace at first, they massacred the Aztecs after seeing their barbaric traditions. In the process, the Aztec leader Moctezuma, who was captured and tried to reason with his people, was killed by his fellow Aztecs. The Spanish, and Borgia, who had managed to retrieve the Crystal Skull from an Aztec priest, managed to escape from Tenochtitlan and return to Spain.

Source

 * Assassin's Creed: Project Legacy - Rome: Chapter 4 - Giovanni Borgia