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)

Migingo is a tiny 2,000-square-metre (0.49-acre; 0.20-hectare) island, about half the size of a football pitch, in Lake Victoria. Migingo is a tiny rock island, less than half-an-acre or about half the size of a football field, located in Lake Victoria, the largest lake in Africa and the largest tropical lake in the world. Although tiny in size, the island is home to 131 people (according to 2009 census) living in crammed huts made of corrugated sheets and wood. Despite shabby living conditions, Migingo Island boasts of five bars, a beauty salon, a pharmacy as well as several hotels and numerous brothels.

Inside the Afar Triangle in Ethiopia’s Danakil desert, camel caravans are used to carry salt. For centuries, the essential mineral has been mined by the Afar people, known for their ability to withstand extremes. The terrain is rugged, travelers are scarce and so are motor vehicles, where the average annual temperature is the highest in the world, and can rise to 122 degrees Fahrenheit, 50 degrees Celsius. (Photo by Ziv Koren/Polaris)

A tourist take a photograph of a sulphur lake in the Danakil Depression on January 23, 2017 near Dallol, Ethiopia. The depression lies 100 metres below sea level and is one of the hottest and most inhospitable places on Earth. Despite the gruelling conditions, Ethiopians continue a centuries old industry of mining salt from the ground by hand in temperatures that average 34.5 degrees centigrade but have risen to over 50 degrees. (Photo by Carl Court/Getty Images)

Visarute Angkatavanich gets incredibly close up to capture these stunning portraits of Siamese fighting fish in graceful, dancerly poses. The Thai photographer uses perfectly placed lighting to create the dramatic highlights and shadows that give personality to each little finned creature.

A boy catches a trout while ice fishing on a frozen river during a fishing contest in Hwacheon, South Korea, Saturday, January 14, 2017. The contest is part of an annual ice festival which draws over 1,000,000 visitors every year. (Photo by /Ahn Young-joon/AP Phot)