A woman hangs strips of salted meat she collected from different places during the Muslim's Eid al-Adha or Festival of Sacrifice, in Lahore, Pakistan, Sunday, August 2, 2020. Pakistanis are celebrating the Eid al-Adha, or the Feast of the Sacrifice, to mark the willingness of the Prophet Ibrahim – Abraham to Christians and Jews – to sacrifice his son. During the holiday Muslims slaughter sheep and cattle, distribute part of the meat to the poor. (Photo by K.M. Chaudary/AP Photo)

A blue crab, a highly invasive alien species, is seen at Lio Piccolo during the reforestation day on April 05, 2025 in Venice, Italy. The island of Lio Piccolo in the northern lagoon of Venice is being replanted with 16,000 new trees that will protect the salt marsh ecosystem that is fundamental to the natural health of Venice and the lagoon by WOWnature project, an Etifor initiative. (Photo by Simone Padovani/Getty Images)

Dan McManus and his service dog Shadow hang glide together outside Salt Lake City, Utah, July 22, 2013. McManus suffers from anxiety and Shadow's presence and companionship help him to manage the symptoms. The two have been flying together for about nine years with a specially made harness for Shadow. (Photo by Jim Urquhart/Reuters)

In this picture taken on Thursday, December 1, 2016, an Iranian woman covers herself with a blanket due to the cold, while visiting Khour salt lake during her tour of the Mesr desert about 305 miles (500 kilometers) southeast of the capital Tehran, Iran. Deserts make up parts of Iran which have recently become tourist destination for young Iranians looking for a break on their weekend. The increase in tourists to the desert has stimulated economic growth in the area. (Photo by Ebrahim Noroozi/AP 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.

A close up of ornaments of centuries-old idols of Lord Buddha during the Pancha Daan, Five donation, festival in Bhaktapur, Nepal, 30 August 2016. Thousands of Buddhist pilgrims observe the main day of the Pancha Daan also known as a five summer gifts (rice, grain, salt, money and fruits) festival which is observes for world peace and human welfare. (Photo by Narendra Shrestha/EPA)

Police detain a protester during a demonstration against the recent gang-rape of a woman in a moving car, according to local media, in Kolkata, India May 31, 2016. A woman was kidnapped and gang-raped by at least four men on May 29 in the Salt Lake area of the city and is currently being treated in hopsital, local media reported. (Photo by Rupak De Chowdhuri/Reuters)

Chris Staring photographs a mysterious train graveyard in the heart of southern Bolivia, where the skeletons of British steam locomotives and rail cars rust away on the edge of the world’s largest salt flats. More than 100 rail cars and locomotives can be found in different states of decay in the train graveyard. (Photo by Chris Staring/Rex Features/Shutterstock)