Divers swim beside millions of silverside fish at Devil's Grotto, Cayman Islands. Swimming in unison, millions of silverside fish dwarf the divers. The fish create waves of silver light as they move around the grottos that lie beneath the surface of the Caribbean Sea. These amazing photographs were captured by Belgian photographer Ellen Cuylaerts, 44, on a diving trip to the Devil's Grotto, Cayman Islands. (Photo by Ellen Cuylaerts/This is Guavo Media)

Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. Millions of these short-lived mayflies engage in a frantic rush to mate and reproduce before they perish in just a few hours during “Tiszaviragzas” or Tisza blooming season from late spring to early summer every year. (Photo by Laszlo Balogh/Reuters)

The incredible detail in each photo is thanks to Jordi Benitez Castells, years of experience taking photos while diving. Jordi, 40, from El Vendrell, Spain, was in Catalunya when he took the photos and managed to get the snaps at about three metres below the surface in most cases. While he works full-time in a bank, Jordi dons his wetsuit out of hours to go diving and uses a Canon 7D to get his shots. Here: One of the beautiful jellyfish. (Photo by Jordi Benitez/Caters News)

A monolith placed in the Utah wilderness in November 2020. New clues have surfaced in the disappearance of the gleaming monolith that seemed to melt away as mysteriously as it appeared in the red-rock desert. A Colorado photographer told a TV station in Salt Lake City that he saw four men push over the hollow, stainless steel structure last Friday night. (Photo by Terrance Siemon/AP Photo)

Ice Age – Tibet, China. “This is the Chinese version of the blue ice lake, Pumoungcuo, at an altitude of 5,070 metres (16,600 feet). This lake in Tibet freezes every winter. At night, under the low temperatures of -20C, you can listen to the sound of the ice cracking while capturing the most beautiful winter sky. The blue ice surface and dazzling Orion constellation create a fantasy landscape. I felt so happy to have the stars as my companion on this magical night”. (Photo by Daniel Zafra Portill/Milky Way Photographer of the Year)

Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

“These stunning ultra-high speed photos of water droplets were captured by photographer, Ronny Tertnes, 48, from Bergen, Norway. They show the water’s displacement as various liquids are being dropped in. Ronny, who works full time as an IT administrator, set up his camera and flash rigs to capture the exact moment a droplet hit the surface, sometimes causing several drops to collide into each other”. – TwoByTwoEditorial.co.uk. (Photo by Ronny Tertnes/TwoByTwoEditorial.co.uk)