Cenotes: Yucatan's Natural Sinkholes
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Cenotes are natural sinkholes filled with fresh groundwater. They form when limestone collapses, and the Yucatan has thousands of them. In Maya tradition, cenotes are sacred openings to the underworld. Today many cenotes are also swimming spots, and some make an easy stop after a Chichen Itza visit.
Last checked: . Cenote types and swimming rules match our individual cenote guides.
Last updated 2026-11-12 · By the local guide team at Maya Explorer Tours
What is a cenote?
A cenote is a natural sinkhole filled with fresh groundwater. It forms when the limestone ground collapses and opens onto the water below. The Yucatan Peninsula has thousands of cenotes.
Why does the Yucatan have so many cenotes?
The Yucatan has so many cenotes because its ground is flat limestone with no surface rivers. Rainwater soaks into the rock and slowly dissolves it, which forms caves full of fresh groundwater. When a cave roof collapses, a cenote opens to the sky. Without rivers, the Maya depended on cenotes for water, and many towns grew up beside them.
An ancient asteroid impact also shaped where many cenotes lie. About 66 million years ago, an asteroid about 10 km across struck near today's Chicxulub Puerto, on the coast north of Merida. The impact is linked to the end of the dinosaurs, apart from the ones that became birds. Its crater is now buried under hundreds of meters of younger limestone, so you cannot see it at the surface. Part of it lies under the Gulf of Mexico.
Around Merida, a ring of cenotes roughly 180 km wide traces the buried rim of the crater, and few cenotes lie inside it. Oil survey data first revealed the buried structure, and scientists confirmed it as an impact crater in 1991.
What types of cenotes are there?
There are three main types of cenotes: open, semi-open and cave.
- Open: like a lake, fully exposed to the sky
- Semi-open: partly covered, often with hanging roots
- Cave: underground with light shafts
How do you swim in a cenote responsibly?
Swim responsibly by keeping the water clean and following the staff rules at each cenote.
- Shower before entering
- No regular sunscreen or repellent
- Life jackets are often provided and sometimes required
Which cenote guide should you read next?
Our nearby cenotes guide compares swim stops close to Chichen Itza. The Ik Kil guide covers the swim stop beside the ruins. The Suytun, Cenote Zaci and Xkeken and Samula guides cover cenotes near Valladolid. The Sacred Cenote inside Chichen Itza is a viewing spot, not a place to swim.
Explore: Cenotes
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Compare cenotes near Chichen Itza: Ik Kil, Yokdzonot, Saamal, Suytun and Zaci, with distances and which one su…
Cenote Zaci is a semi-open cenote in the center of Valladolid, Yucatan. See what to expect, how to swim safely…
Xkeken and Samula are two cave cenotes at Dzitnup, just outside Valladolid. See the light beams, tree roots, s…
What else do visitors ask about cenotes?
Were cenotes created by the asteroid?
Cenotes form when limestone collapses over groundwater, and the asteroid impact shaped where some of them appear. The ring of cenotes around Merida follows the edge of the buried Chicxulub crater. That crater shaped how the limestone fractured, so many cenotes line up along its rim.
What does the word cenote mean?
Cenote comes from the Yucatec Maya word ts'onot, which Spanish speakers wrote down as cenote. It means a well or a hole with water. English uses the same word, cenote, for a natural sinkhole where limestone has collapsed over groundwater. In Spanish, a cenote is a pool of spring water, usually below ground level.