The Sun Stone, also known as the Aztec Calendar Stone, is a large monolithic sculpture created by the Aztecs in the 15th century. It is made of basalt and measures about 3.6 meters in diameter. The stone features intricate carvings that represent various aspects of the Aztec cosmology, including the sun god Tonatiuh and the five worlds of creation. Originally, the Sun Stone was believed to serve as a calendar, marking the passage of time and important rituals. It was discovered in 1790 in the main square of Mexico City and is now housed in the National Museum of Anthropology.