Cenote (pronounced Sen-o-tay) is a Yucatan Mayan word meaning any sinkhole with accessible groundwater. For thousands of years, these cenotes have been the wells, providing water for the villages and towns dotted around them. They are formed because the bedrock here is limestone. Rainwater hitting limestone is a little like trying to hold water in a colander. It seeps through the bottom and drips down below. Eventually it will hit sturdier rock and will be allowed to pool. Hence the lakes, in the Yucatan, all being underground.
Yet, as the water filters through the rock, it dissolves it, undermines it or erodes it. In some areas, this finally becomes too much and the roof collapses, exposing the pool to the open air. Thus the cenote is formed around crystal clear water, filtered by its slow passage through the rock. For the local human population, it's a source of life, spirituality and entertainment.
There are thousands of cenotes on the Yucatan Peninsula. Some are tiny, some are vast; some are self-contained bowls, some are the access points to a sprawling subterranean maze of rivers and caverns; some are shallow, some are deep; some are major tourist attractions, fitted with piers, springboards, rappel lines and all the comfort amenities, and some are hidden away in people's backyards. More are discovered all the time. Building work and landscaping can suddenly uncover a cenote. They are usually a welcome addition to the scenery.
For generations of locals and tourists alike, cenotes are a spectacularly beautiful place to refresh, after a trek through the jungle or a visit to the Maya ruins. Not only is it shaded in a cenote, but the water is deliciously cool. Some, like Ik Kill, near to Chichen Itza, are always full of bathers. They enter with a look of serene relief, then bob about in the water, with smiles on their faces. It's the purity of the water; the beauty of the scenery; and the sense of the sacred, in this hidden world.
Of course, sacred is right, because many of these cenotes meant more than just accessible drinking water and a place to bathe for the Maya people. In many cenotes, votive offerings have been found. The legends and histories also make it clear that, for the ancient Maya, these cenotes acted as holy places. They were the natural cathedrals.
Sometimes, this religious feeling had darker overtones. In the Cenote Sagrado (Sacred Sinkhole), within the grounds of Chichen Itza, there have been found ancient human bones. This was where human sacrifice was offered to the gods of the underworld. Elsewhere on the Yucatan, in Sahcaba, a whole underwater complex of Maya temples were discovered in 2008. It was believed that the Maya viewed this as an access to the land of the dead.
If you are in Mexico, please don't pass up the chance to swim in a cenote. It is a sublime experience that will remain with you for years - a little piece of paradise on Earth.