Lebanese university students wearing municipality police costume regulate the traffic in the village of Brummana, east Beirut, Lebanon, 23 June 2018. The touristic town of Brummana is making a daring move in anticipation of the crowded summer season, by forming a group of young policewomen wearing mini shorts to regulate the traffic. (Photo by Wael Hamzeh/EPA/EFE)

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 tattoo of Captain America drawn by artist Sean Karon on the leg of client Ron Raucci at the Hampton Roads Tattoo Festival in Virginia, on March 2, 2012. The tattoo was completed from start to finish in one five-and-a-half hour session and won the prestigious “tattoo of the day” contest. (Photo by Jason Reed/Reuters)

Havilland Mosquito KA 114 performs a low pass during an airshow commemorating the completion of its rebuild on September 29, 2012 in Ardmore, New Zealand. The plane was restored by Warbird Restorations at Ardmore Aerodrome and is the only flying Mosquito in the world. (Photo by Simon Watts)

An employee stands on the step of The Venice Simplon-Orient-Express at Istanbul Station in Istanbul, on August 31, 2022. The Venice Simplon Orient-Express luxury train arrives in Istanbul, completing its annual voyage along a mythical route that takes it across Europe from Paris. (Photo by Yasin Akgul/AFP Photo)

A mountain hare shakes off rain from its fur, in Findhorn Valley, Moray, Scotland in the second decade of August 2024. In summer, the hare’s coat is a grey-brown colour with a tinge of blue, making them hard to spot against the heather moorland. In winter, it changes to almost completely white for camouflage in the snow. (Photo by Will Hall/Solent News)

Canadian slackliner Mia Noblet walks on a slackline (25mm wide, 3mm thick and 60m long) during “Tianmen Mountain Female High-Heeled Highline Challenge” at Zhangjiajie National Forest Park on May 27, 2018 in Zhangjiajie, Hunan Province of China. 23-year-old Canadian slackliner Mia Noblet became the first one who finished the challenge in 22 minutes and 36 seconds while 32-year-old French slackliner Mini Guesdon broke the record in 9 minutes and 24 seconds during her second attempt on Sunday. (Photo by VCG/VCG via Getty Images)

British actress Laila Rouass poses during a studio shoot ahead of the new series of “Footballers Wives” at a London studio on January 28, 2004 in London. Rouass plays Conrad's bisexual wife Amber, and the nine-part series begins on ITV1 on February 11, 2004. (Photo by Stephen Perry/Getty Images)