Aztec Sun Stone

It is the centerpiece of the Sala Mexica at the Museo Nacional de Antropología in Mexico City, one of the largest museums of its kind. It has been there since the museum's opening in 1964. It is mounted on a wall at ground level in the central hall.

Scholars disagree on whether it is a calendar, a ritual monument, or a symbolic representation of Mexica cosmology and past cosmic ages. The central face is often identified as Tonatiuh, the sun deity. Surrounding ring panels show the 20 day signs of the 260-day ritual calendar.

The basalt monolith weighs approximately 24 tons and measures about 12 feet or 3.6 meters across. It was carved from a single block. Moving it required special rigs during its various relocations.

It was rediscovered in 1790 during repairs to the Mexico City Cathedral plaza, the Zócalo, near the site of the Templo Mayor. It had been buried after the Spanish conquest in 1521. It was initially mounted on the cathedral's western tower before moving to the museum.