About 65,000,000 years ago, during the Cenozoic Era, the Yucatan Peninsula was covered by the ocean and therefore corals. During the Ice age, the level of the ocean dropped and left many reefs and their dependent marine life exposed to air. As a result, the calcium-rich remains of marine plants, algae, mineral and animals accumulated and sedimented over geological time solidified these sediments into a rock material named limestone. Many fossils remain embedded in this rocks and some of them are quite easy to spot during a dive.

In time, the slightly acidic rainwaters dissolving the alkaline limestone and passing through the ground flowed slowly towards the ocean started craving huge underground systems with hundreds of tunnels and dozens of caves fully decorated with speleothems (stalactites, stalagmites, columns) formed by mineral deposits, (most of them are made up of crystallized calcium carbonate), that can evolve into any shape or form.

Over time, in some of those tunnels, the ceiling collapsed, either by the rainwaters craving the limestone rock or by the impact of the Chicxulub asteroid. Scientists are still arguing over whether the Chicxulub impactor was the killing blow for the dinosaurs, but what we do know was that it was so catastrophic that it liquidized a chunk of the Earth's crust and created a crater in the Yucatan Peninsula 180 Km/ 112 miles wide creating one of the most breathtaking natural wonders of the world, the Ring of Cenotes (includes around 900 cenotes).

When the Ice Age came to a close 18,000 years ago, the climate of the planet warmed up, the glaciers receded and the caves flooded as the sea level rose to its current level around 1,000 years ago. Meanwhile, carbon dating artefacts found in some of these cave areas shows that these caves have been visited by humans over 9,000 years ago.

Cenotes were a vital part of life for the Mayans, there are very few rivers and lakes in Yucatán, so the sinkholes were their primary source of freshwater. This is why it's often to find remains of major Maya settlements close to cenotes.
The Mayan word for cenotes is “d'zonot”, meaning deep and abysmal, they believed that some of these natural wells were the gateways to the underworld or afterlife, therefore, they considered it as sacred areas and often made offerings to them and threw valuable items into the water as sacrifices. These sacrifices to the Mayan rain deity Chaac weren’t always limited to things, as some tribes even sacrificed live humans. During underwater explorations of the Sagrado Cenote (Sacred Cenote) at Chichen Itzá, archaeologists found the remains of several human bodies, including males, females, and children.

Diving in a Cenote is a unique experience. These caverns are windows to the world’s largest underground river systems and the water is so clear that the visibility can go over 152 meters/ 500 feet, which make your cavern diving adventure absolutely unforgettable.
In some Cenotes, you will see beautiful speleothems, fossils, amazing light effects as the sunlight shines through the cracks in the ceiling, air domes with bats, halocline and hydrogen sulfate layer effects.
There are many cenotes in the area, all different and special and with an Open Water Diver certification, it is possible to dive into some of these incredible caverns.