Cenote vs sinkhole

The simple answer

Every cenote is a sinkhole, but not every sinkhole is a cenote. A sinkhole is any hole or dip in the ground caused by rock dissolving or collapsing underneath. A cenote is a sinkhole deep enough to reach groundwater, so it holds clear fresh water. The word comes from the Yucatec Maya word dzonot, meaning a well or water hole.

Side by side

• Water: cenotes always reach the water table; many sinkholes are dry.
• Rock: cenotes form in limestone (karst); sinkholes also form in gypsum, salt and even soil over pipes.
• Speed: cenotes formed over thousands of years; some sinkholes open suddenly in a day.
• Place: 'cenote' is used mainly for the Yucatán Peninsula and nearby; 'sinkhole' is used worldwide.
• Culture: cenotes were sacred water sources and portals to the underworld for the Maya.
• Danger: sudden sinkholes can swallow roads and houses; cenotes are stable visitor sites.

How both form

• Rainwater absorbs carbon dioxide and becomes a weak acid.
• It seeps into limestone and slowly dissolves caves underground.
• Solution sinkholes: the surface slowly dissolves into a bowl.
• Collapse sinkholes: a cave roof gets too thin and falls in. Most cenotes formed this way.
• If the hole reaches groundwater, it becomes a cenote.

Types of sinkholes

• Dissolution (solution) sinkholes: slow, bowl-shaped dips.
• Cover-subsidence sinkholes: sand slowly sinks into gaps below.
• Cover-collapse sinkholes: sudden collapse of the ground, common in Florida.
• Man-made sinkholes: caused by broken pipes, mining or pumping groundwater.

Types of cenotes

Cenotes are grouped by how open they are: open (like a pond), semi-open (partly under a rock roof), cave or cavern (mostly underground) and ancient (old cenotes now mostly filled in). See our types of cenotes guide.

Famous examples

• Cenotes: Ik Kil, Suytun, Dos Ojos, the Sacred Cenote at Chichén Itzá.
• Dry sinkholes: Guatemala City's 2010 sinkhole (reported caused partly by pipes), the Xiaozhai Tiankeng in China.
• Water-filled sinkholes outside Mexico: Florida springs, the Bahamas' blue holes, El Zacatón in Tamaulipas.

Blue holes vs cenotes

Blue holes, like Belize's Great Blue Hole or Dean's Blue Hole in the Bahamas, are sinkholes now in the sea or near the coast. They formed the same way when sea levels were lower. Cenotes are mainly inland and filled with fresh water, sometimes with saltwater deep below.

Cenote vs cave vs sinkhole

A cave is an underground space. A sinkhole is a hole at the surface. A cenote can be both: a sinkhole that opens into a water-filled cave. Many cenotes look like caves inside because only a small part of the roof has fallen.

Why the Yucatán has so many cenotes

The peninsula is a flat slab of limestone with no surface rivers, so rain soaks down and dissolves the rock. The groundwater sits close to the surface, so collapses usually reach water and become cenotes instead of dry sinkholes.

Are sinkholes dangerous in the Yucatán?

New collapses do happen, sometimes under roads or fields, but they are rare and local. Visitor cenotes are established, stable sites. The bigger risk to people is slipping on wet stairs, not collapse.

Cenotes and the aquifer

Every cenote is a window into one large aquifer that supplies drinking water to the region. A dry sinkhole has no such link. That is why cenotes are protected and why pollution entering one can spread far underground.