An Indian man stands near his house as waves caused by high tide hits the huts on the shore of the Arabian Sea in Mumbai, India, Wednesday, July 3, 2019. Heavy monsoon rains in Maharashtra have led to more than 30 deaths since Monday night, from collapsed walls, drownings and other causes. Dozens of others have been injured. (Photo by Rafiq Maqbool/AP Photo)

Men rest after salvaging metal on the 30th floor of the “Tower of David” skyscraper in Caracas February 3, 2014. A 45-storey skyscraper in the center of Venezuela's capital Caracas is a slum, probably the highest in the world. Dubbed the “Tower of David”, the building was intended to be a shining new financial center but was abandoned around 1994 after the death of its developer – banker and horse-breeder David Brillembourg – and the collapse of the financial sector. (Photo by Jorge Silva/Reuters)

A woman reacts as rescuers search for survivors through the rubble of collapsed buildings in Adana, on February 6, 2023 after a 7,8 magnitude earthquake struck the country's south-east. The combined death toll has risen to over 1,900 for Turkey and Syria after the region's strongest quake in nearly a century. Turkey's emergency services said at least 1,121 people died in the earthquake, with another 783 confirmed fatalities in Syria. (Photo by Can Erok/AFP Photo)

Two women look at the Cumbre Vieja volcanic eruption from the distance in Los Llanos de Ariadne in La Palma, Canary Islands, Spain, late 05 October 2021 (issued 06 October 2021). The main cone of the La Palma volcano suffered a partial collapse of its structure 03 October, while effusive activity has increased after 15 days of its beginning. According to experts the volcano is far from ending its volcanic activity. (Photo by Miguel Calero/EPA/EFE)

In this Saturday, June 24, 2017 file photo, Zeid Ali, 12, left, and Hodayfa Ali, 11, comfort each other after their house was hit and collapsed during fighting between Iraqi forces and Islamic State militants in Mosul, Iraq. The Ali cousins said some of their family members are still under the rubble. (Photo by Felipe Dana/AP Photo/File)

An aerial view of sinkholes (obruk), caused by some form of collapse of the surface layer, in Konya, Turkiye on September 17, 2024. Many sinkholes are observed in the fields of Eseli Plateau located within the borders of Resadiye Neighborhood in the north-west of Karapinar district, where sinkhole formation has increased rapidly in recent years. (Photo by Serhat Cetinkaya/Anadolu via Getty Images)

An exterior view of Rauceby, an abandoned mental asylum in Lincolnshire, UK. These haunting photos show the collapsing remains of a derelict mental asylum. The pictures show the ruined former hospital building and chapel, now covered in dust and graffiti. Few signs remain that reveal the site as a former home of mentally ill adults and children. (Photo by Simon Robson/Caters News)

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.