What is a cenote ?
It’s a specific phenomenon known to this region of Mexico. A cenote (from the Mayan word “ts’ono’ot) is a natural water hole that gives access to spectacular caverns filled with fresh water on the surface and salt water deeper. They are formed by limestone collapsing and dissolution above the underground river and cave systems.
Millions of years ago, the Yucatan peninsula was a coral reef plunged several meters deep. During the Ice Age, the sea water level decreased, leaving to appear a giant limestone plate in which jungle land developed.
Among the different reasons for the birth of these immense rivers are the decrease in the ocean water level and the impact of a meteorite that fell on the northern part of the Yucatan peninsula (Chicxulub), 65 million years ago. The same that participated in the extinction of dinosaurs.
Around 18000 years ago, at the end of the Ice Age, the sea water level rapidly increased more than 65 m and caves filled with water. That's the reason why we are nowadays able to scuba dive in the cenotes. You will be immerged in an area with crystal clear water where stalagmites, stalagtites and prehistoric bone formations will make your dive like a visit to a natural history museum.
Cenotes were considered sacred places by Mayans, being the entrance to the Xibalba: the divine underworld, territories of the gods and the source of life. They were the only source of fresh water for them.
Cenotes can be in diverse forms: open air wells, deep lakes or caves. They can be found in the middle of a jungle, in the sea, in mangroves or in the middle of a city.
The formation of a cenote is in several stages: first a cave, then the roof collapses and creates a cylinder type cenote that little by little and year after year the lime stone plates form types of lakes.
But that’s not all. Cenotes are extremely interesting on an archaeological point of view. Local cave diving archaeologists have recently discovered in several different cenotes near Tulum, fossilized remains of animals (camelides, giant jaguars, tapirs, mammoths and sloths) and human skeletons. Some of the most ancient remains in Latin America belong to a woman born in this region than 10000 years ago. The discovery represents an interesting idea on the presence of man in the beginning of America.
One can understand the importance the INAH (National Institute of Archaeology and History) devotes to the cenotes and the rules one must always respect: never touch anything and take back only beautiful memories.