Alligators and an egret stand on the banks of the Bento Gomes river next to the Transpantaneira road at the Pantanal wetlands near Pocone, Mato Grosso state, Brazil, Monday, September 14, 2020. A vast swath of the vital wetlands is burning in Brazil, sweeping across several national parks and obscuring the sun behind dense smoke. (Photo by Andre Penner/AP Photo)

A woman walks near a bus on fire as supporters of Brazil's President Jair Bolsonaro protest after supreme court justice Alexandre de Moraes ordered a temporary arrest warrant of indigenous leader Jose Acacio Serere Xavante for alleged anti-democratic acts, in Brasilia, Brazil on December 12, 2022. (Photo by Ueslei Marcelino/Reuters)

Fans gather to watch a FIFA World Cup Russia 2018 football match between Brazil and Costa Rica on a giant screen at Alzirao neighborhood in Rio de Janeiro, Brazil on June 22, 2018. (Photo by Carl De Souza/AFP Photo)

A spectator reacts after a Brazil Volleyball win during Paris 2024 Olympics in Women's Preliminary Round, Pool B Brazil vs Poland at South Paris Arena 1 in Paris, France on August 04, 2024. (Photo by Siphiwe Sibeko/Reuters)

Officers react at their graduation ceremony during Iraqi Army Day anniversary celebration in Baghdad January 6, 2015. Iraqi Defence Minister Khaled al-Obeidi said on Tuesday that the Iraqi military has started rebuilding after its near total collapse last summer but that the effort is still in its initial phase. (Photo by Ahmad Mousa/Reuters)

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.

Dancers perform on their way to attend a rally with former President Luiz Inacio Lula da Silva, “Lula”, supporting President Dilma Rousseff in the historic Lapa neighborhood on April 11, 2016 in Rio de Janeiro, Brazil. Brazil's congressional impeachment committee approved the motion to proceed with President Dilma Rousseff's impeachment process today. A full vote by the lower house of Congress on the impeachment is scheduled for Sunday to decide whether she will face trial. (Photo by Mario Tama/Getty Images)

Aerial view of the Christ The Protector Statue and the Valle de Taquari on April 20, 2021 in Encantado, Brazil. The statue being built in Encantado, southern Brazil, will surpass the iconic Christ The Redeemer of Rio de Janeiro by seven meters. Made of steel and concrete, it will stand 43 meters including its pedestal, and become the third-tallest statue of Jesus Christ in the world. (Photo by Buda Mendes/Getty Images)