Police gesture in respect towards a monk as they block protesters trying to march to the Asia-Pacific Economic Cooperation APEC summit venue, Friday, November 18, 2022, in Bangkok, Thailand. (Photo by Wason Wanichakorn/AP Photo)

Ferrari's Spanish driver Carlos Sainz Jr celebrates winning the Singapore Formula One Grand Prix night race at the Marina Bay Street Circuit in Singapore on September 17, 2023. (Photo by Mohd Rasfan/AFP Photo)

Participants hold flags during a demonstration lesson that is part of an extracurricular military-patriotic program, which involves weapon training, first aid treatment, camping skills and other courses, in Sevastopol, Crimea on May 19, 2023. (Photo by Alexey Pavlishak/Reuters)

A goat hops from student to student during a goat yoga class at the University of Tennessee on August 25, 2022 as part of welcome back week. The session was organised by Goat Yoga Nashville. (Photo by Matt Hamilton/Chattanooga Times Free Press via 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 coach wipes away tears and comforts a girl who was feeling tired during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, May 4, 2016. (Photo by Aly Song/Reuters)

A women attends a class at a driving school in Kabul August 17, 2014. Kabul is one of the world's fastest growing cities and its streets are increasingly blocked by cars and buses. In the city's private driving schools, students pay a $60 fee for a 45-day course, which includes oral and practical driving tests at the country's Traffic Department. Some of the women who have signed up say learning to drive is a way to escape unwanted gazes and physical harassment on the cramped, crowded minibuses that are often the only method of urban public transport. (Photo by Mohammad Ismail/Reuters)

A woman jumps over a puddle of rainwater in north London on August 2, 2023. Met Office has issued a yellow severe weather weather for heavy downpours, strong winds and thunderstorms throughout today in London, and in many other parts of England and Wales. (Photo by Dinendra Haria/London News Pictures)