North Korea's Samjiyon Orchestra performs at Pyongyang Grand Theatre in Pyongyang, North Korea, September 18, 2018. (Photo by Pyeongyang Press Corps/Pool via Reuters)

The jewelled flower mantis, commonly found in Asia, is believed to be the inspiration for many martial artists is seen in Jakarta, Indonesia on August 2, 2016. (Photo by Prabu Dennaga/Barcroft Images)

Astronauts Harrison Schmitt (left) and Eugene Andrew Cernan practice taking geological samples at the Kennedy Space Center in Florida, in preparation for NASA's scheduled Apollo 17 lunar landing mission, on August 28, 1972. Schmitt is the Lunar Module Pilot and Cernan is the mission's Commander. They are training for their period of EVA (extravehicular activity) on the Moon. (Photo by Space Frontiers/Getty Images)

A woman prays during a gathering with other devotees for the ritual prayers for Laylat al-Qadr (Night of Destiny), one of the holiest nights during the Muslim fasting month of Ramadan, outside the Imamzadeh Saleh mosque in Tehran, on April 10, 2023. (Photo by Atta Kenare/AFP Photo)

A woman throws olives into a freshly-harvested pile beneath a tree, during the harvest season in Khan Yunis in the southern Gaza Strip on October 5, 2023. (Photo by Said Khatib/AFP Photo)

A dog looks on, as dogs and humans take part in the annual Paris Sausage Walk, also known as the march of the dachshunds, in Paris, France, on November 17, 2024. (Photo by Kevin Coombs/Reuters)

A racoon jumps over a fence in almost deserted Central Park in Manhattan on April 16, 2020 in New York City. Gone are the softball games, horse-drawn carriages and hordes of tourists. In their place, pronounced birdsong, solitary walks and renewed appreciation for Central Park's beauty during New York's coronavirus lockdown. The 843-acre (341-hectare) park – arguably the world's most famous urban green space – normally bustles with human activity as winter turns to spring, but this year due to Covid-19 it's the wildlife that is coming out to play. (Photo by Johannes Eisele/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.