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)

Women pose for a selfie at Ipanema Beach in Rio de Janeiro, Brazil on July 30, 2016. (Photo by Nacho Doce/Reuters)

Russian fashion model Irina Shayk bares it all while getting ready for the Rio Carnival parade in Brazil early March 2025. (Photo by irinashayk/Instagram)

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.

Syrian Tulin Hashemi waits for a job interview at a hotel in Vidigal slum in Rio de Janeiro, Brazil, September 22, 2015. Tulin, whose mother arrived two days ago, has been living in Brazil for two months. As she does not speak Portuguese, Tulin says it is difficult for her to find a job and therefore she is staying at the slum as it is one of the cheaper neighbourhoods to live in. According to the National Committee for Refugees (CONARE), 2,077 people fleeing the Syrian civil war have settled in Brazil, whilst a quarter of the 8,400 refugees in the Latin American country come from Syria. (Photo by Pilar Olivares/Reuters)

A woman dressed up for Halloween travels on a Metro train in São Paulo, Brazil on October 30, 2017. (Photo by Cris Faga/Rex Features/Shutterstock)

Rihanna celebrates by flashing the crowd on July 13, 2014 in Rio de Janeiro, Brazil. (Photo by Twitter.com)