A woman holds up what the Chris Steaks & Burgers restaurant says is Thailand's biggest burger weighing more than 6 kilograms, before a competition held to eat it at the restaurant in Bangkok, Thailand, October 11, 2019. Chris Steaks and Burgers is offering a 10,000 baht ($330) prize for anyone who can finish the mammoth snack in nine minutes – one baht for every calorie. (Photo by Jiraporn Kuhakan/Reuters)

Migrant children play with leaves during Christmas Eve at a shelter, as they travel with their parents as part of a caravan with humanitarian visas to transit throughout the country, in Monterrey, Mexico on December 24, 2021. (Photo by Daniel Becerril/Reuters)

Women dressed in traditional costumes sing Christmas carols as they gather to celebrate Orthodox Christmas at a compound of the National Architecture museum in Kyiv, Ukraine on January 7, 2022. (Photo by Valentyn Ogirenko/Reuters)

Nicolo Martinenghi of Italy competes in the Men's 50m Breaststroke Final on day six of the 2022 FINA World Short Course Swimming Championships at Melbourne Sports and Aquatic Centre on December 18, 2022 in Melbourne, Australia. (Photo by Daniel Pockett/Getty Images)

Txai Suruí, Amazonian Activist, during the opening night of Web Summit Rio 2023 at Riocentro in Rio de Janeiro, Brazil. (Photo By Stephen McCarthy/Sportsfile for Web Summit Rio via Getty Images)

Daniel Sheridan, a council worker from Poole, Dorset, runs a side hustle snapping dogs living their best lives in the second decade of December 2024. (Photo by Daniel Sheridan/South West News Service)

A man looks at a statue of the Greek god Poseidon on a beach during the passage of tropical storm Beryl in Progreso, on the Yucatan Peninsula, Mexico, on July 5, 2024. Beryl weakened to a tropical storm Friday after hitting Mexico as a Category 2 hurricane, with fierce winds causing material damage but no injuries along the tourist-rich Yucatan Peninsula. (Photo by Hugo Borges/AFP 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.