Kandy Freeman participates in a Black Lives Matter protest in front of Trump Tower in New York City, U.S. January 14, 2017. (Photo by Stephanie Keith/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.

A participant dances as approximately 70,000 people from all over the world gathered for the annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. on August 29, 2017. (Photo by Jim Urquhart/Reuters)

Children take part in the “Carnavalito” children's parade during the Blacks and Whites Carnival in Pasto, Colombia, on January 2, 2018. (Photo by Juan Barreto/AFP Photo)

A guest’s hands at the Essence Black Women in Hollywood awards luncheon at the Beverly Wilshire Four Seasons hotel in Beverly Hills, California on March 24, 2022. (Photo by Image Press Agency/NurPhoto/Rex Features/Shutterstock)

Danish model Helena Christensen looked stunning as she posed in lacy, black negligee in garden of her New York home on December 2, 2022. (Photo by Coco De Mer)

American singer-songwriter Miley Cyrus in the last decade of January 2023 lounges in shades and rocks a sharp black bikini. (Photo by Dolce Glow by Isabel Alysa/Instagram)

A black-winged stilt patrols a reservoir in Jezreel Valley in Israel early April 2023. Their eggs are a golden colour mottled with brown. (Photo by Itamar Procaccia/Solent News)