White horses of the Camargue thunder through the shallow salt flats at sunset on December 8, 2022. Known as Horses of the Sea, the breed native to the wetlands in southern France is one of the oldest in the world. (Photo by Nathalie Mountain/Media Drum Images)

A monolith placed in the Utah wilderness in November 2020. New clues have surfaced in the disappearance of the gleaming monolith that seemed to melt away as mysteriously as it appeared in the red-rock desert. A Colorado photographer told a TV station in Salt Lake City that he saw four men push over the hollow, stainless steel structure last Friday night. (Photo by Terrance Siemon/AP Photo)

People take part in a protest outside the Department for Education, London, Sunday August 16, 2020, in response to the A-level results. The British government has been urged to “get a grip” over how grades are being awarded to school students, who were unable to take exams earlier this summer because of the coronavirus pandemic. The latest confusion emerged late Saturday when England’s exam regulator launched a review on its own just-published guidance on how students can appeal grades awarded under a complicated system. (Photo by London News Pictures/The Sun)

"La Montagna di Sale (The Salt Mountain)" by Mimmo Paladino is displayed in Piazza Duomo on April 5, 2011 in Milan, Italy.

Chinese security stands near a Long March 2F rocket carrying Tiangong-1, China's first unmanned space module, stands at the Jiuquan Satellite Launch Center on September 28, 2011 in Jiuquan, Gansu Province of China. Tiangong-1,a small unmanned space lab, will be launched at 21:19 (Beijing time) on September 29, 2011, and will attempt a docking procedure with a Shenzhou 8 spacecraft later in the mission. (Photo by Lintao Zhang/Getty Images)

Ra Paulette is an American cave sculptor based in New Mexico who digs into hillsides to sculpt elaborate artistic spaces inside mountains. Reviewer Martha Mendoza in the Los Angeles Times described the caves he created as shrines, as hallowed places, a “sanctuary for prayer and meditation” while others describe the caves as works of art. The caves are finished with “scallops, molded curves, smooth ledges, inlaid stones, narrow pods and crusty ledges”. His caves attract visitors worldwide.

In this May 21, 2021, file photo, JoJo Hamner, a cast member of the “Sexxy After Dark: Where Dinner Meets Play” show, gets the Pfizer COVID-19 vaccine during a pop-up vaccine clinic at Larry Flynt's Hustler Club in Las Vegas. It's one of several methods health officials are employing here and across the country to bring vaccines directly to people to counter waning demand. In tiny towns, ballparks, strip clubs, and marijuana dispensaries, officials are setting up shop and offering incentives to entice people who so far have not gotten shots. (Photo by Ellen Schmidt/Las Vegas Review-Journal via AP Photo/File)

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.