An egret in the second decade of April 2025 cools off in the Florida heat by gular fluttering, rapidly vibrating its throat muscles with an open beak. The mechanism helps to dissipate heat through evaporation. (Photo by Ronen Tivony/ZUMA Press Wire/Alamy Live News)

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.

Loreen from Sweden performs after winning the 2023 Eurovision Song Contest in Liverpool, Britain on May 14, 2023. (Photo by Phil Noble/Reuters)

The Japanese punk rock garage quartet Otoboke Beaver perform at Maggie Mae's at the South by Southwest (SXSW) Music Film Interactive Festival 2017 in Austin, Texas, U.S., March 17, 2017. (Photo by Brian Snyder/Reuters)

A model holds a dog presenting a creation by Anthony Rubio during New York Fashion Week, in New York City, U.S., September 13, 2025. (Photo by Caitlin Ochs/Reuters)

A pedestrian carries an umbrella as they stroll past an advertisment as a rainstorm moves through Sacramento, Calif., Wednesday, February 13, 2019. Rain is falling widely in Northern California and is expected to spread south. (Photo by Rich Pedroncelli/AP Photo)

Nefertara, a supporter of pop star Britney Spears, wears an outfit inspired by the singer as she holds a picture of Britney that she painted, during a gathering on the day of a conservatorship case hearing at Stanley Mosk Courthouse in Los Angeles, California, U.S., September 29, 2021. (Photo by Mario Anzuoni/Reuters)

A tourist pets a cat before the “Horus protects Ramses II as a child”, dating to the reign of the Ancient Egyptian New Kingdom pharaoh (1303-1213 BC), at the Egyptian Museum in the centre of Egypt's capital Cairo on October 19, 2022. (Photo by Amir Makar/AFP Photo)