Cenotes and caves are two words you’ll hear when visiting Mexico’s Yucatan Peninsula, often confused, mixed up, or used interchangeably… it’s worth knowing these terms, and maybe even coming to see these natural wonders!
What is a cave?
A cave is a natural hollow cavity or opening that extends past the natural light zone. It sounds simple as a definition, but there is one key element often considered: for it to be a cave and not only a hole, it is typically large enough for a human to enter. Exploration, therefore, is what sets apart a cave, from a hole…
Going down the rabbit hole of caves is a fun, enlightening experience. How can holes in the ground be such a source of fascination for us? We can look at caves from many angles, often overlapping: geology, history, paleontology, biology, chemistry, hydrology, anthropology, and archaeology, to name a few.
There are also many types of caves, and speleogenesis (the formation of caves) is a topic in itself. The majority of caves in the world exist in karstic landscapes. Karst is a type of terrain formed by sedimentary rocks. This means the rock can erode and dissolve over time, creating openings large enough for us to enter.
The Yucatan Peninsula is a karstic region that holds the largest underwater cave system in the world. Currently, Ox Bel Ha has been surveyed at over 540 km of explored passages. Together with many other systems, big and small, they make the state of Quintana Roo the Mecca of cave diving. But why is that?
If you look at a photo of Quintana Roo from above, you’ll mostly see the jungle—and nowadays also a train that cuts through of the forest, but let’s leave that aside. The jungle canopy shelters the ground beneath, but if we could remove that layer and look only at the bare terrain, what we would see is something like a sieve: the ground perforated with holes of all sizes. Many of them are not only large enough for a human, but big enough to fit an airplane… these openings are the world-famous cenotes.
This terrain has often been compared to Swiss cheese, but a sponge is a better analogy—water doesn’t just flow through pipe-like tunnels, it permeates the rock itself.
If we looked at this “sieve” from above, we would see thousands of collapses, cracks, depressions, crevices, and openings. We would also notice that there are no rivers going through the Peninsula. That’s because the ground is so porous that water seeps through the rock and accumulates underground.
The openings leading to the peninsula’s main (and only) freshwater reserve underground, the Cenotes.
Photo by @mekanphotography
So… what is a cenote?
These openings are what we call cenotes but what about similar features in other regions, are there cenotes in other countries?
Yes—and no.
Collapses, dolines, and openings into underground water exist in many parts of Mexico and the world, but cenotes have a unique combination of geological and cultural characteristics.
Photo by @mekanphotography
The word “cenote” comes from the Maya term ts’ono’ot, often translated as “abyss.” While similar geological features exist worldwide, the term “cenote” is used specifically in the Yucatan due to its unique geological and cultural context.
The Maya understood the life-sustaining importance of cenotes. Like many ancient civilizations, they settled around water sources. But the cenotes also played a central role in Maya cosmology, culture, and religious practices.
If a similar opening is found elsewhere, it is more likely to be called a sinkhole, doline, spring, or well.
Where cenotes meet caves
It’s safe to say that most cenotes provide access to cave systems. Their passages lead below the surface into a complex network of tunnels and chambers, many of them interconnected. But some cenotes don’t lead to a cave, they are simply fresh water pools and have no horizontal section.
Were the Maya able to explore these caves? Evidence suggests the Maya used caves and cenotes for ritual and daily purposes, but did not explore deeply flooded sections as modern cave divers do. When the Maya civilization thrived, most of these caves were already flooded, with water levels similar to today, making deep exploration impossible.
However, long before the Maya civilization, the first humans to populate the American continent did explore these caves. Due to sea level drop, the water level was lower than today and therefore the caves were dry. The first inhabitants of the American continent walked through them, used them for shelter, and relied on them for resources and protection from predators and environmental conditions.
Photo by @divewells
These caves preserve a timeline of human presence—from Ice Age people over 10,000 years ago to Maya activity in the last millennium.
That’s why inside cenotes and the caves they lead to, we can find Ice Age fossils, fire pits, cairns, and evidence of ochre mining and organized human activity. And from later periods, we find ceramics, vessels, and clay items used or deposited by the Maya.
In the Yucatan Peninsula, human remains have also been found inside caverns and caves, including pre-ceramic skeletons in Quintana Roo and Maya remains in cenotes across Yucatan—some showing cranial and dental modification.
Photo by @mekanphotography
A living system
Today, cenotes continue to be studied. The caves, like a vast puzzle with millions of pieces, are still being explored, documented, and researched—perhaps now more than ever.
At the same time, cenotes are social spaces for local communities. People gather by the water to eat, socialize, swim, and connect. As cave divers, we may enter the aquifer through a small, muddy pond to discover the striking beauty of the deep, dark caves—but we should not forget that what is above is connected to what lies below… and neither can exist without the other.
A shared responsibility
The two priorities of cave divers should always be safety and conservation. But this applies to non-divers as well. Preserving cenotes in all their forms is essential to protecting these fragile systems.
The sponge-like marvel of the cenotes can only endure if we care for them—so that future generations can enjoy them, regardless of how many cylinders they carry… or if they carry any at all.
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Written by Tamara Adame
Tamara is a self taught underwater naturalist from Puerto Morelos, Mexico. She has spent most of her life around water and is an Open Water Scuba Instructor and cave diving guide. She holds a BSc in Communication and a Scientific Diving diploma which has allowed her to work in environmental conservation projects and motivated her to launch the Cave Corals Project in 2020.
