Templo Mayor Tour, Mexico City: Aztec Ruins & Museum

Templo Mayor was the ceremonial center of Tenochtitlan. It stayed buried under Mexico City until 1978, when electric company workers hit a carved monolith and an entire block of the historic center had to come down. First, the open-air ruins: the platforms of the twin pyramid built for Tlaloc and Huitzilopochtli. Then the museum, where your guide walks you through the main pieces and the recent finds.