A cenote is a natural sinkhole that is formed by the collapse of limestone bedrock, exposing groundwater underneath. Cenotes can vary in size and shape, ranging from small openings to large, water-filled caverns.

Cenotes often have crystal-clear, turquoise-colored water. Cenotes were considered sacred and were important water sources. Today, cenotes are popular tourist attractions, offering opportunities for swimming.

When it comes to cenotes, most people usually think of the Yucatan Peninsula.

Yucatan is home to the Ring of Cenotes, the unique creation of which is associated with the fall of the Chicxulub meteorite, which marked the end of the age of dinosaurs and created a crater with a diameter of 180 km.

The Yucatán Peninsula is made up of a thick limestone platform, which over millions of years has been eroded by natural processes. The impact of the Chicxulub meteorite created fractures and weaknesses in this limestone, contributing to the formation of the Ring of Cenotes.

There are at least 7,000 cenotes, or underground wells, in the Yucatan, where they were sacred sites to the Mayans.

El Zacatón is the deepest cenote in the world

However, the deepest cenote in the world is not in the Yucatán Peninsula. Although Yucatan is mostly associated with cenotes, the deepest cenote in the world is located in a completely different Mexican state, Tamaulipas.

Zacatón is a thermal water-filled sinkhole that is part of a group of unusual karst formations near the Sierra de Tamaulipas. With a total depth of 339 m, it is one of the deepest known water-filled sinkholes in the world.

How deep is the El Zacatón cenote? With a diameter of 140 meters, El Zacatón is 339 m deep, which makes it the deepest cenote on the planet. The depth was verified using a robotic submarine called DEPTHX, the mission sponsored by NASA.

The Deep Phreatic Thermal Explorer (DEPTHX), which carried out the exploration, was created by Carnegie Mellon University as part of its tests to go to Europa, one of Jupiter’s moons, and the mission was sponsored by NASA.

This robotic submarine (DEPTHX) confirmed that the cenote’s depth was 319 meters, with an additional 20 meters added from the ground to where the water starts. This means that the total depth of the cenote is 339 meters.

El Zacatón - the deepest cenote in the world

El Zacatón cenote is not open for recreational swimming, and diving is extremely dangerous, restricted to scientific or highly specialized technical cave divers. Several divers have died attempting to explore its depths.

El Zacatón is part of a complex karst system with submerged caves and tunnels. The water contains sulfur compounds, reflected in the nearby ranch’s name, La Azufrosa, which affects the water’s clarity and gives it a characteristic odor.

Surrounded by steep rocks, El Zacatón is located in the Rancho La Azufrosa, about 2 hours from Tampico, in a place known for its eco-tourism, geological formations, lagoons, and a wide diversity of flora and fauna.

The Zacatón is connected to 4 other interconnected cenotes that surround it:

  • Poza Verde
  • Caracol
  • Pilita
  • Poza Azufrada

These cenotes are generally accessible to visitors, though access may vary.