Lake Assal is a crater lake in central-western Djibouti. It is located at the western end of Gulf of Tadjoura in the Tadjoura Region, touching Dikhil Region, at the top of the Great Rift Valley, some 120 km (75 mi) west of Djibouti city. Lake Assal is a saline lake which lies 155 m (509 ft) below sea level in the Afar Triangle, making it the lowest point on land in Africa and the third-lowest land depression on Earth after the Dead Sea and Sea of Galilee.

Vogue Italia is hosting a series of shows in Milan exploring how the magazine seeks to engage with hot social and political issues and provoke debate through images by top photographers. The Photo Vogue festival in Milan is hosting three exhibitions. The first, Fashion and Politics in Vogue Italia, looks at the magazine’s ambition to be a catalyst for change – in subtle and playful ways. Here: David LaChapelle – October 2004. (Photo by David LaChapelle/The Guardian)

Members of a samba school warm up before parading along Copacabana Beach in Rio de Janeiro, Brazil, Saturday, January 6, 2018. Musicians and members from Rio de Janeiro's top 13 samba schools have paraded in an event aimed at promoting tourism ahead of Rio's world famous Carnival that begins early next month. (Photo by Leo Correa/AP Photo)

Participants in the Grelka Fest at the Sheregesh resort in Tashtagolsky District of Kemerovo Oblast, Russia on April 22, 2017. Russian girls marked the end of the ski season with a record-breaking bikini ski festival at Siberia’s top winter resort, Sheregesh. Some 1,498 skiers and snowboarders undressed to impress in the annual event as they took to the pistes under blues skies and sunshine in a bracing temperature of just 5°C. (Photo by Grelka Fest/The Siberian Times)

English singer Dua Lupa, 25, poses in Puma Mayu trainers in her latest advertising campaign for the brand in Herzogenaurach, Germany on August 16, 2021. The singer posed in the new suede trainers and a black skirt and top with chainmail underneath. Dua Lipa is featured in Puma's latest women's brand campaign “She Moves Us”, which, celebrates women who move together to achieve and connect through fashion, community and sport. (Photo by Mario Sorrenti)

The British Wildlife Photography Awards winners have been revealed, with Lee Acaster from Suffolk taking home the top prize for his shot of a Graylag Goose in London. Acaster, who received £5,000, photographed the animal against an ominous London skyline, with The Shard clearly visible in the background. Here: “Urban Tourist (Graylag Goose)”. Urban category and overall winner. (Photo by Lee Acaster/British Wildlife Photography Awards 2014)

These photographs are the work of urban explorer Dr Bradley Garrett who made headlines back in 2012 when he posted a series of snaps from the top of The Shard skyscraper while it was still under construction. Garrett, now a researcher at the University of Oxford, took these shots during his time with the London Consolidation Crew (LCC), a loose collection of urban explorers based in the English capital. Photo: Bradley Garrett stands on the edge of the Ritz-Carlton Chicago as lightning strikes in the distance in Chicago, US. (Photo by Bradley L. Garrett/Barcroft Media)

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.