Cenotes are natural sinkholes or pits that result from the collapse of limestone bedrock, exposing groundwater. They are common geological forms in low-altitude regions, particularly on islands, coastlines, and platforms with young post-Paleozoic limestone with little soil development. Cenotes are surface connections to subterranean water bodies, and while the best-known cenotes are large open-water pools measuring tens of meters in diameter, the greatest number of cenotes are smaller sheltered sites and do not necessarily have any surface exposed water. Cenotes may be fully collapsed, creating an open water pool, or partially collapsed with some portion of a rock overhanging above the water.

Cenotes are found primarily throughout the Yucatan Peninsula in Mexico, where they were commonly used for water supplies by the ancient Maya, and occasionally for sacrificial offerings. The term cenote originated on the Yucatán Peninsula of Mexico, and the word derives from a word used by the lowland Yucatec Maya—tsʼonoʼot—to refer to any location with accessible groundwater.

Cenotes come in all sorts of different shapes and sizes, and the most common types of cenotes are cave, semi-open, and open cenotes. Cave cenotes are the youngest, and the open cenote is the oldest as its cave ceiling has fallen into itself. The open cenotes or open-air cenotes are the most visited, easily accessible, and the oldest, as a result of the collapse of limestone until the water has been exposed on the surface. Semi-open cenotes can be considered an entrance to the "underworld" or "Xibalba" and have some holes to let in the daylight and provide a view over the beautiful chamber and its spectacular cave formations.

Cenotes are deep water wells, which are fed by the filtration of rain and the currents of the rivers that are born in the heart of the earth. The flora and fauna of a cenote are unique, and there are species of fish such as guppy and catfish, as well as some varieties of marine crustaceans. Turtles, iguanas, frogs, and butterflies live in the surroundings, as well as swallows and Toh Birds, better known as the bird of the cenotes.

In conclusion, cenotes are natural sinkholes or pits that result from the collapse of limestone bedrock, exposing groundwater. They are found primarily throughout the Yucatan Peninsula in Mexico and come in all sorts of different shapes and sizes. Cenotes are deep water wells, which are fed by the filtration of rain and the currents of the rivers that are born in the heart of the earth, and the flora and fauna of a cenote are unique.