A cenote is a type of sinkhole found in the limestone shelf that comprises much of Mexico's Yucatan peninsula. They are frequently filled with water as they are often below the local water table, and for the communities historically found through the area, were sometimes the only source of fresh water. This made them incredibly important places for veneration and ritual, and were seen as both portals to the underworld as well as linked to certain Deities, including Chaak.