A flood affected boy on a makeshift banana raft collects biscuit packets distributed by a government official from a boat in Pokoria village, east of Gauhati, north eastern Assam state, India, Monday, August 14, 2017. Heavy monsoon rains have unleashed landslides and floods that killed dozens of people in recent days and displaced millions more across northern India, southern Nepal and Bangladesh. (Photo by Anupam Nath/AP Photo)

A child stops by a large print at a photographic memorial for those killed in the confrontation between Ukraine's military and the pro-Russia separatist forces in Sievierodonetsk, Luhansk region, eastern Ukraine, Wednesday, February 23, 2022. Ukraine urged its citizens to leave Russia, and Europe braced for further confrontation Wednesday after tensions escalated dramatically when Russia's leader received authorization to use military force outside his country and the West responded with a raft of sanctions. (Photo by Vadim Ghirda/AP Photo)

Residents push a makeshift raft loaded with a motorcycle through floodwaters brought about by heavy rains in Propseridad town, Agusan del Sur province on southern Mindanao island on February 1, 2024. Floods and landslides triggered by torrential rain have killed six people in the Philippines, with one other person missing, rescuers said February 1. (Photo by Erwin Mascarinas/AFP Photo)

People wash in water from a broken water pipeline on the outskirts of Kolkata, India, March 30, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A Kashmiri Muslim woman balances on a water pipe before collecting water at Dasilpora village on March 22, 2018. World Water Day is held annually on 22 March as a means of focusing attention on the importance of freshwater and advocating for the sustainable management of freshwater resources. (Photo by Tauseef Mustafa/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.

A tourist splashes water on the frozen Songhua River on December 18, 2023 in Harbin, Heilongjiang Province of China. The water immediately freezes into ice in the frigid air. (Photo by VCG/VCG via Getty Images)

A group of riders splash down a water slide in Bromont, Que on Monday, June 29, 2020 as water parks reopen in the province of Quebec, Canada. (Photo by Canadian Press/Rex Features/Shutterstock)