In this handout image provided by Red Bull, Jessica Macaulay of Canada dives from the 22 metre platform during the final competition day of the sixth stop of the Red Bull Cliff Diving World Series on September 11, 2022 at Sisikon, Switzerland. (Photo by Romina Amato/Red Bull via Getty Images)

A person dressed as a zombie mermaid poses for a photo as she interacts with patrons at the Haunted Hotel Takeover Halloween party at hotel Ziggy in West Hollywood, California, U.S., October 29, 2022. (Photo by Mario Anzuoni/Reuters)

A boy and a woman run across a railway track as a train approaches in Chengdu, Sichuan province, China, October 8, 2015. Many residents disregard sign prohibiting this kind of illegal crossing and choose to do so to save time, local media reported. (Photo by Hao Fei/Reuters/Western China Metropolis Daily)

A visitor poses with a 3D art work during a Japanese Trick Art exhibition at a shopping mall in Jakarta, Indonesia, Tuesday, December 4, 2012. (Photo by Dita Alangkara/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.

“Lombard Street is an east-west street in San Francisco, California. Lombard Street is best known for the one-way section on Russian Hill between Hyde and Leavenworth Streets, in which the roadway has eight sharp turns (or switchbacks) that have earned the street the distinction of being the crookedest street in the world”. – Wikipedia

Photo: A single car drives down a typically crowded Lombard Street, San Francisco's crooked street, April 29, 2003 in San Francisco. (Photo by Justin Sullivan/Getty Images)