American singer-songwriter Miley Cyrus in the last decade of January 2023 lounges in shades and rocks a sharp black bikini. (Photo by Dolce Glow by Isabel Alysa/Instagram)

A black-winged stilt patrols a reservoir in Jezreel Valley in Israel early April 2023. Their eggs are a golden colour mottled with brown. (Photo by Itamar Procaccia/Solent News)

Pasua Turner jumps double dutch as people take part in a Juneteenth event along Black Lives Matter Plaza on Monday June 19, 2023 in Washington, DC. (Photo by Matt McClain/The Washington Post)

Dawlish Carnival 50th anniversary pram race featuring the famous Dawlish Black Swan in England on August 15, 2023. (Photo by nidpor/StockimoNews/Alamy Live News)

American model Emily Ratajkowski was seen monday, October 3, 2023, waking around Manhattan in a black sheer dress and high heels. (Photo by Said Elatab/The Mega Agency)

An adult black-rumped flameback woodpecker is pestered by a pair of hungry chicks in Rajarhat, India in the second decade of May 2024. (Photo by Kalyan Acharya/Solent News)

From the top of a building, Kanon Kennedy, of Washington, looks down at the Black Lives Matter mural as demolition begins, Monday, March 10, 2025, in Washington. (Photo by acquelyn Martin/AP Photo)

A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.