Asia Sawicka as Anastasia IV poses for a photograph prior to a rehearsal of the Circus of Horrors' latest show Voodoo, ahead of Halloween, at the Wookey Hole Caves Theatre near Wells on October 19, 2017 in Somerset, England. (Photo by Matt Cardy/Getty Images)

National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)

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.

Hindu pilgrims walk along a mountain path as they make their pilgrimage to the sacred Amarnath Cave, one of the most revered Hindu shrines, near Baltal, Kashmir, India. (Photo by Daniel Berehulak)

Soccer player David Beckham (C) with Cruz Beckham (L) and Romeo Beckham (R) get slimed onstage during Nickelodeon Kids' Choice Sports Awards 2014 at UCLA's Pauley Pavilion on July 17, 2014 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

A Guinean kid poses for a photo in Conakry, Guinea on July 23, 2021. Children, most of whom start working after a certain age to support their families, have their hair braided in different ways and decorated with colorful beads on all special days, especially on holidays, despite these difficult conditions. (Photo by Ozkan Bilgin/Anadolu Agency via Getty Images)

Instructor Raquel Potí leads a stilt walking workshop at the Museum of Modern Art in Rio de Janeiro, Brazil, Saturday, January 27, 2024. Potí is chiefly responsible for the explosion of stilt walking in Rio, having trained more than 1,000 kids and adults over the past decade. (Photo by Silvia Izquierdo/AP Photo)

Some creations from the new “Funny Food Made Easy” book by Bill and Claire Wurtzel. “Inspiring kids to eat healthy foods with creative works of plate art and easy-to-follow instructions and illustrations. Through finished plate art, detailed step-by-step illustrations, recipes, and tips, Funny Food Made Easy provides all you and your kids need to make, eat, and enjoy healthy breakfasts, lunches, and snacks” – roughly speaking so. Here: Egg, cucumber, olive. (Photo by Bill and Claire Wurtzel/Welcome Books)