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.

“The 53rd Annual TV WEEK Logie Awards is an upcoming event to be held on Sunday 1 May 2011 at the Crown Entertainment Complex in Melbourne, and will once again be televised on the Nine Network. The awards ceremony will be hosted by Shane Bourne, marking the first time he has hosted the event. American singer-songwriter Katy Perry will open the Logie Awards performing her hit single “Firework”. Maroon 5 and Jessie J will also perform. Andre Rieu will not perform but will present an award”. – Wikipedia


Photo: Singer Katy Perry arrives on the red carpet ahead of the 2011 Logie Awards at Crown Palladium on May 1, 2011 in Melbourne, Australia. (Photo by Scott Barbour/Getty Images)

Mug shot of William Stanley Moore, 1 May 1925, Central Police Station, Sydney. This picture appears in the Photo Supplement to the NSW Police Gazette, 28 July, 1926 captioned: “Opium dealer. Operates with large quantities of faked opium and cocaine. A wharf labourer; associates with water front thieves and drug traders”. (Photo by NSW Police Forensic Photography Archive, Justice & Police Museum, Histiric Houses Trust of NSW)

A squatter argues with a police officer during an eviction at a settlement coined the “First of May Refugee Camp”, named for the date people moved on the land designated for a Petrobras refinery, in Itaguai, Rio de Janeiro state, Brazil, Thursday, July 1, 2021, amid the new coronavirus pandemic. (Photo by Silvia Izquierdo/AP Photo)

People attend the Immortal Regiment march on Victory Day, which marks the 77th anniversary of the victory over Nazi Germany in World War Two, in the village of Bobrovka in the Omsk Region, Russia on May 9, 2022. (Photo by Alexey Malgavko/Reuters)

Emma Raducanu of Great Britain receives treatment in her women's singles first round match against Bianca Andreescu of Canada during day three of Internazionali BNL D'Italia at Foro Italico on May 10, 2022 in Rome, Italy. (Photo by Alex Pantling/Getty Images)

Nigerians take a photo in their traditional clothes during Eid al-Fitr prayers in Lagos, Nigeria on May 2, 2022. Muslims gather to perform Eid al-Fitr prayers held in Nigeria, the country with the largest Muslim population in Africa. (Photo by Adeyinka Yusuf/Anadolu Agency via Getty Images)

A poster depicts a disinfection worker in North Korea on May 23, 2022. The COVID outbreak in the isolated country, confirmed about two weeks ago, has stoked concerns about a lack of vaccines and medical supplies, while experts said a nationwide lockdown could deepen a food crisis in the country of 25 million. (Photo by KCNA via Reuters)