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Cenotes: The Underwater Caves of The Riviera Maya, Mexico

Cenotes: The Underwater Caves of The Riviera Maya, Mexico

Written by Charly Stringer
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Updated on September 28, 2023
diver exploring a cenote in The Riviera Maya

The state of Yucatán, Mexico, is home to some of the most beautiful and intricate underwater caves and caverns. These are accessible through entry points or sinkholes known as cenotes (underwater caves). Cenotes (pronounced say-noh-tays) are actually a type of freshwater-filled limestone sinkhole. These natural wonders are known to connect with other underlying cave systems that can be explored for lengths of 100 kilometers or more.

The famous cenotes of the Yucatan peninsula in Mexico are filled with magical history around how they were formed and what they were used for. Today, tourists flock to Mexico to take a selfie or to scuba dive at the beautiful cenotes. We are going to look at how the cenotes were originally formed, and go through all the information you need to go scuba diving there.

cenote diving
Image via Shutterstock

What are cenotes?

So, what is a cenote? A cenote is a sinkhole that formed naturally from collapsing limestone bedrock. The collapsing bedrock exposes water that’s underground. The vast majority of cenotes are in the Yucatan peninsula of Mexico, which is estimated to have around 10,000 cenotes across the area, however the cenotes spread as far as Belize and Guatemala in fewer numbers.

History of cenotes: How they formed

The ancient Mayans commonly used the cenotes as their source of water, but they were sometimes also used for sacrificial offerings. But how were the magical Mexican cenotes formed?

Many years ago the area to the southeast of Mexico was just a coral reef covered by seawater. Over time the sea levels dropped, which caused the barrier to be exposed, and eventually it died and became a tropical forest. After the last ice age occurred, rainfall began in the area and the rainwater mixed with carbon dioxide in the atmosphere. This made carbonic acid, which became more acidic when it came into contact with the soil on the ground.

The soil has high levels of decomposing organic matter, and so more carbonic acid was created which had a corrosive effect. The mixture of salt water with fresh water also took a toll on the limestone rock and overtime holes began to form. These holes grew in size over time and even formed tunnels and passages that linked them together. This is what we now call the cenotes.

Types of cenotes

Here are the main types of cenotes:

Open cenotes

Open cenotes are the type that most people recognize. They are surrounded by vegetation and are populated by numerous fauna. This type of cenote is found in the middle of wetlands or within mangroves and they are one of the oldest types of cenotes.

Semi-open cenotes

A semi-open cenote is well recognized for its “pitcher” shape. They were formed by a small opening in the top of the cenote, and the diameter of the cenote increases considerably internally, especially where the water surface is, and continues to get wider below. To get inside a semi-open cenote, you have to go through the upper cavern.

Closed cenotes

Closed cenotes are the youngest type of cenote. They are circular and closed by a vault. Closed cenotes may or may not have openings on the surface which allow sunlight inside. You can access these cenotes through passages, caves, or tunnels that are found at water level, but accessing a closed cenote depends on whether the water level is safe. Stalagmites and stalactites are found in large quantities in closed cenotes.

Deep open cenotes

Deep cenotes are the most popular amongst tourists because they are completely open and cylindrical in shape, and they have high, vertical walls. The Sacred Cenote of Chichen Itza is a deep open cenote and is the most famous worldwide.

Most Famous Cenotes in Mexico

There are over 3,000 cenotes (caves) in the Yucatán Peninsula, with only 1,400 of them having been studied and recorded. These cenotes are located between Cancun and Tulum and The Riviera Maya. The Riviera Maya has the world’s three longest-running underwater cave systems: Sistema Ox Bel Ha (270.2 km), Sistema Nohoch Nah Chich (67 km), and Sistema Dos Ojos (82.47 km).

Cenotes were once sacred places of the Mayans, as they were said to represent entrances to the underworld (known as Xibalba). Their natural beauty—best described as crystal clear turquoise waters with sunlight reflecting stalactites and stalagmites—are truly enigmatic works of art that scuba divers from all over the world can’t help but explore.

Listed below are five of the most notable cenotes of the Riviera Maya:

Cenote Chac Mool

About 22 kilometers south of Playa Del Carmen and across the Puerto Aventuras lies the Chac Mool Cenote. Chac Mool (which means the “Claw of the Jaguar”) has two entries, both leading to a relatively large cavern with a lot of natural light entering from the opening. This cavern leads to a Dome Room. Here, a portion of the ceiling has collapsed under an air dome where divers can surface to admire a huge number of beautiful stalactites and some fossils. Since the maximum depth is about 12 meters (36 feet), Chac Mool is the perfect spot for novice cavern divers.

sun beams penetrating the waters of Cenote Chac Mool
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Cenote Kukulkan

A couple of hundred feet away from Cenote Chac Mool is another entrance to the Chac Mool system, called Cenote Kukulkan. During sunny days on the Kukulkan side, you can witness an amazing light show as sunlight reflections create rainbow colors that reach towards the ceiling.

Cenote Dos Ojos

This famous and popular cenote is situated one kilometer south of Xel-Ha and roughly 48 kilometers from Playa del Carmen. The name “Dos Ojos” means “two eyes,” and is derived from the two circular-shaped cenotes that are located very close to each other.

In the 1980s, the Dos Ojos and Nohoch Nah Chich cave systems were discovered through a competition involving two exploration teams that aimed to determine the longest running underwater cave system in the world.

Two dives are conducted in Dos Ojos. The first starts in the first eye (situated in the east) and progresses through a crystal clear freshwater cavern leading to the second eye (situated in the west). The second dive is a darker dive into a series of rooms and passages underneath an air-filled “bat cave,” which receives very little sunlight. This dive features passageways filled with beautiful and fragile speleothems.

With about 60 kilometers of explored length and connections to over 25 cenotes, Dos Ojos is one of the longest systems in the Yucatán Peninsula. It’s a great cenote for non-divers too, as you can snorkel through the shimmering caves.

Cenote Dos Ojos, Mexico
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Cenote Taj Mahal

About 29 kilometers south of Playa del Carmen are four interconnected cenotes with much to offer both cavern and cave divers. One of the most beautiful cenotes in The Riviera Maya, Cenote Taj Mahal boasts a cavern filled with light streaming through holes in the ceiling. As the fresh water creates a distinct layer over the salt water, haloclines appear in deeper areas and create an interesting mirror-like effect.

Gran Cenote

One of the most popular cenote sites in The Riviera Maya, Gran Cenote is part of Sistema Sac Actun. Ladder steps lead to a half moon shaped cenote decorated with small passages and openings. Explorers will enjoy a spectacular array of large stalagmites, stalactites, and columns by sticking their face into the water without having to dive in. Good buoyancy control is required if you are diving here as the walls are heavy with the formations. The maximum depth is said to be 21 meters (70 feet).

Gran Cenote, Mexico
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Diving in cenotes: what you need to know

There are different options available for all kinds of divers wanting to scuba dive in the cenotes. Some cenotes offer open water divers, some offer cavern dives, and some offer cave dives. Here is the difference:

Open Water dives

As many cenotes are not caves or have tunnel systems, many cenotes offer the opportunity to make open water dives, and some have shallow, pool-like conditions that are suitable for doing confined water dives, too. This means it is possible to take courses at the cenotes, and make open water dives in shallow cenotes, or in deeper cenotes that offer the depth in which you are certified to dive to, without having to have any cave diving experience.

Cave diving

A cave is usually considered a cave when it has no sign of natural light, it has narrow passages, and it is deeper than 60ft or it’s over 200ft from the entrance. Cave diving is highly technical and absolutely requires special training in planning and risk management. Certified and experienced cave divers will find many exciting options at the cenotes to have a good exploration through the deep caves and extensive tunnel systems.

Cavern diving

A cavern is different to a cave in that it will have ambient light available, and is close to open water. This ensures it is easy to swim out and get to the surface in an emergency. Some dive centers in the Yucatan peninsula offer divers the chance to explore caverns within the cenotes, without having to go fully inside a cave. Training level depends on the cenote and the dive center but an Advanced Open Water diver certification is adequate for many, although you might need to prove a minimum amount of logged dives, too.

Conclusion

The cenotes are so fascinating and unique and are a very exciting scuba diving experience. Book your dives before you get there and find out what certifications and experience you need for your desired cenotes. With so many divable cenotes there really is an option for every level of diver.

 

Charly Stringer

Charly Stringer

Charly Stringer is a scuba diver based in Dahab, Egypt. She is a scuba diving and freediving instructor, as well as a digital creator,