Cenotes are places where the ground sinks when the water table drops and leaves a void, and the sinkholes opens up a cavern filled with water that's been filtered for ages. Chichen Itza is built on a large cenote.
Cenotes are a big part of life on the peninsula. Tourists love to snorkel and scuba dive in the cenotes, which can be inhabited by eels, fish, frogs, and catfish. There are 4 different types of cenotes, from caves to caverns to simple sinkholes. But did you know there's a ring of sinkholes around Chichen Itza?
The ring of cenotes makes up the circle of the Chicxulub Crater. This crater has been dated to between the Cretaceous and Paleogene periods, 66 million years ago. It is the site of a huge meteorite impact. This meteorite impact happened at the point when the Cretaceous period gave way to the Paleogene period and is associated with the mass extinction of the dinosaurs. It's known as the Cretaceous–Paleogene extinction event. Yep. You read that right. The cenotes were created because of a meteorite hit that blasted the Yucatan and likely contributed to the extinction of the dinosaurs. Who knew?
The cenotes were believed to be a Gateway to the afterlife, by the Mayans. So although they used them for water, they also threw everything from valuables to humans into some of them. Just during the 20th century, explorers found mastodon bones in the cenotes along with skulls and skeletons of human beings, including one known as Eve of Naharon and the skeleton of a teenage girl, dating from around 13,500 years ago. Remember, the Mayans didn't show up until 11,000 years later!
Explorers have been scuba diving in the cenotes and are only now trying to map them. The caves in The Yucatan are the largest connected complex of caves in the world. And when divers get deep enough, they come across what's called the heliocline. That's where the fresh water mixes with the salt water from the ocean. I don't understand how these bodies of water interact, but apparently the scholars don't consider the ocean to be "connected" to the cenotes, per say. I can't explain it. They mingle but aren't connected. Like frat boys with out-of-their-league college girls. I don't understand and I'm not going to try.
Just imagine swimming in a cenote, diving to 300 ft and coming across the heliocline! It's a cloudy, swirling plane of sea water mixing with fresh water and they say it's hard to see there because of the swirling saltwater. I don't have any dive certifications so I won't be diving on my trip, but I bet it's an amazing experience. For that matter, I bet swimming in a cenote is an amazing experience even if you're not diving. I'm so excited to try!




