The Aztec Calendar Stone, also known as the Sun Stone, is a large monolithic sculpture created by the Aztec civilization in the early 16th century. It measures about 3.6 meters (12 feet) in diameter and is made of basalt. The stone features intricate carvings that represent the Aztec cosmology, including the five worlds of the sun and various deities. Discovered in 1790 in Mexico City, the stone is often mistakenly thought to be a calendar. Instead, it serves as a symbolic representation of the Aztec understanding of time and the universe. Today, it is displayed at the National Museum of Anthropology in Mexico City.