Cenote

A type of natural well or reservoir, common in the Yucatán Peninsula, Mexico, formed when a limestone surface collapses, exposing water underneath. Cenotes are the major source of water in Yucatán and they are associated with the cult of the rain gods, or Chacs. In ancient times, especially at the Maya site of Chichén Itzá, precious objects, such as jade, gold, copper, and incense - and human beings, usually children, were thrown into the cenotes as offerings. A survivor was believed to bring a message from the gods about the year's crops.

The limestone formations of the arid Yucatan peninsula in Mexico are honeycombed with water-filled underground caves. The collapse of the roofs of some of these caves causes a kind of natural well, or cenote. These became the major source of water for Mayan and subsequent groups in the area. These formations also had some ritual significance. The Sacred Cenote at Chichen Itza, for example, contained a considerable amount of skeletal material together with luxury items such as jade, gold and copper. This material seems to confirm legendary accounts of human sacrifice.