Doodlewatch

The Aztec calendar stone, Mexica sun stone, or Stone of the Sun (Spanish: Piedra del Sol), is a large monolithic sculpture that was excavated in the Zócalo, Mexico City’s main square, on December 17, 1790.

Measuring about 3.6 metres (12 ft) in diameter, 1.22 metres (4 ft) in thickness and weighing 24 tonnes, the original basalt version is presently on display at the National Museum of Anthropology in Mexico City’s Chapultepec Park. Images from the Sun Stone appear on the reverse of Mexican peso coins of all denominations. This basalt sculpture is a representation of the Aztec calendar.

• http://en.wikipedia.org/wiki/Aztec_calendar_stone