A visit to the colonial city of Merida on Mexico’s Yucatan Peninsula, is not complete without exploring one of the region’s most important geographic icons: the “cenote” (in Maya “dzonot”, which translates as “cave with water”). “Cenote” refers to any subterranean chamber that contains permanent water, and while some are vertical, water-filled shafts, others are caves that contain pools and underwater tunnels and passageways that crisscross their interior.
Cenotes formed due to a combination of global climate changes and eons of geological events. Many millions of years ago the Yucatan Peninsula was an ocean reef set under several feet of seawater that was subsequently exposed during the last ice age, when water levels dropped approximately 300 feet lower than their present day levels, thus exposing the reef to the surface. Marine coral and other fauna died and eventually formed a mile thick limestone platform that today is the land mass called the Yucatan Peninsula.
Over thousands of years massive, intricate cave systems were formed by the gradual dissolving of the highly porous coral limestone. These cave systems are called “solution” caves because they were formed by the slightly acidic rainfall dissolving the alkaline limestone. Inside these then dry caves millions of geological formations grew, including stalactites (hanging from the cave ceilings), stalagmites (growing upwards from the cave floors), and many other fascinating varieties.
Many of the caverns eventually collapsed and 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 sea levels rose. These collapsed cave ceilings now served as entry points into this vast water world below and it was because of these that early human settlers were able to survive in a landscape that otherwise offers no access to fresh water.
The Mayans grew to be the dominant culture in the region and visible evidence of the importance of the cenotes is the close proximity of these to all of their ancient and modern towns and cities. When visiting any of the famous or even lesser known Mayan ruins be sure to set aside time to explore and appreciate the cenotes that made their centuries-long survival possible.