The Cenotes of the Yucatan: How the Maya Used Sinkholes as Doorways to the Underworld

The Yucatan Peninsula has no surface rivers. No lakes to speak of either. A vast limestone shelf sits just below the ground. Over millions of years, rainwater has dissolved passages through it. This process has created one of the largest underground river systems on Earth. In places, the ceiling of these underground passages collapses, and a hole opens to the sky. You look down and see turquoise water 30, 60, 100 feet below ground, perfectly still, perfectly clear. It is connected to rivers that run for miles in every direction under the rock.

The Maya called these openings ch’en. There are over 6,000 of them documented across the Yucatan, and geologists think there may be over 10,000 total. They were the only freshwater source in the region. This shaped everything about where Maya cities were built and how they were organized. But the Maya did not think of them only as wells. Instead, they thought of them as doorways.

What Xibalba Actually Was

Before getting into what the Maya did at cenotes, it’s worth correcting a common misunderstanding about Xibalba, the Maya underworld.

Xibalba was not the Maya version of Hell. In Maya cosmology, it was not a place of punishment for the wicked. Nearly all souls went to Xibalba after death, regardless of how they had lived. The concept is closer to the Greek Hades: a general realm of the dead, a place of transition and transformation rather than damnation. Notably, the word Xibalba translates roughly as “Place of Fear,” which captures the mood without implying moral judgment.

The underworld had multiple lords, with names like One Death and Seven Death. It consisted of multiple regions with different trials and challenges. The Maya creation epic, the Popol Vuh, tells the story of the Hero Twins Hunahpu and Xbalanque. They descend into Xibalba to avenge their father’s death and ultimately defeat the lords of death. Their victory over the underworld lords explained the cycles of death and rebirth. This governed the Maya understanding of the world.

Cenotes were, in Maya cosmology, the physical openings to this realm. The dark, still water far below the surface, the way sound echoed in the limestone chambers, the transition from the bright world above to the shadowed world below—all of it mapped perfectly onto the idea of a threshold between the living world and the realm of the dead.

The Sacred Cenote at Chichen Itza

The most famous cenote in the Maya world sits at the northern edge of Chichen Itza, one of the most visited archaeological sites in the Americas. The Sacred Cenote, also called the Well of Sacrifice, is about 200 feet across and drops roughly 65 feet to the water surface. The water itself is another 65 feet deep. It is not particularly beautiful as cenotes go. The water is dark green and murky from the organic material that has accumulated over centuries.

What has been recovered from it is extraordinary. In the early 20th century, American archaeologist Edward Thompson purchased the site and had the cenote dredged. The operation recovered jade objects, gold discs, pottery, copal incense, carved wooden objects, rubber balls, and human remains. Over the following decades, Mexican archaeologists conducted systematic underwater excavations and recovered over 30,000 objects and the remains of at least 42 individuals.

The human remains included men, women, and children. Skeletal analysis found evidence of injuries consistent with sacrifice on some but not all of the individuals. The cenote appears to have functioned as a major pilgrimage site, receiving offerings from across the Maya world over a period of many centuries. In fact, people came from significant distances to make offerings here.

The idea that the Maya primarily threw young women into the cenote as sacrifices, which circulated widely in early 20th-century popular accounts, is not supported by the archaeological evidence. The remains represent a range of ages and both sexes. Additionally, many cenotes received no human remains at all.

The Geology Underneath Everything

The cenotes exist because of limestone, deep time, and one specific catastrophe from 66 million years ago. The Yucatan Peninsula is essentially a flat limestone shelf built up from ancient coral reefs and marine sediment over millions of years. Rainwater, slightly acidic from absorbing carbon dioxide as it falls, slowly dissolves the limestone as it percolates downward. Over millions of years this process creates vast networks of underground caves and rivers. When cave ceilings become too thin to support their own weight, they collapse. As a result, cenotes open at the surface.

Here is the specific catastrophe: many researchers now believe that the ring-shaped distribution of cenotes across the northern Yucatan traces the edge of the Chicxulub impact crater. At this site, an asteroid roughly 6 miles across hit the Earth 66 million years ago and triggered the mass extinction that killed the non-avian dinosaurs. The impact fractured the limestone bedrock in a ring pattern, and water has been flowing through those fractures ever since. This process created caves that became cenotes. The Maya were, in a sense, conducting their ceremonies to the underworld at the geological scar left by one of the most catastrophic events in Earth’s history. They had no way to know this. The geometry is striking anyway.

Visiting Them Now

The Yucatan has cenotes of every type: open-air pools like the Sacred Cenote, semi-open cenotes with partial cave ceilings, cave cenotes that require swimming through underground passages, and dry cenotes that can only be entered on foot. Most are accessible to tourists. In fact, swimming in them is one of the stranger and more beautiful experiences available in the region.

The water is cold, roughly 75 degrees Fahrenheit year-round, filtered through miles of limestone and clear enough to see the bottom even at significant depth. Freshwater fish and turtles live in many of them. Cave divers have mapped hundreds of miles of underwater passages connecting the cenotes, and the system is still being explored. Importantly, the longest known underwater cave system in the world runs through the Yucatan.

The practical issue in 2026 is contamination. The underground aquifer that feeds all the cenotes is also the primary drinking water source for the entire Yucatan Peninsula, including Cancun and its millions of annual visitors. Sunscreen washed off by tourists, agricultural runoff, and inadequately treated sewage from the region’s rapid development all percolate down through the limestone into the same water table. The Maya considered the cenotes sacred because they provided life. They were right about that, more literally than even they understood.