A man looks at waves as they crash against a lighthouse in the northern Spanish village of Viavelez, Spain January 13, 2017. (Photo by Eloy Alonso/Reuters)

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.

People watch a forest fire in Funchal, Madeira Island, Portugal, 09 August 2016. The fire has led to the evacuation of 400 people. Portugal remains on high alert as a wave of wildfires has swept the country with around 350 isolated fires affecting swathes of the countryside. (Photo by Gregório Cunha/EPA)

A police officer walks along a street of the burning village of Smolenka near Chita on Monday, April 13, 2015. Russian authorities say out-of-control agricultural fires have killed at least 15 people, injured hundreds more and destroyed or damaged more than 1,000 homes in Siberia. The fires were started by farmers burning the grass in their fields, but spread quickly because of strong winds. (Photo by Evgeny Yepanchintsev/AP Photo)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

Kent Josephso organizes his 8mm tracer rounds during the Big Sandy Shoot in Mohave County, Arizona March 23, 2013. The Big Sandy Shoot is the largest organized machine gun shoot in the United States attended by shooters from around the country. Vintage and replica style machine guns and cannons are some of the weapons displayed during the event. Picture taken March 22, 2013. (Photo by Joshua Lott/Reuters)

General view of the stands in the Atrium during the Big Fashion Wardrobe Spring/Summer fashion and beauty event at Westfield London shopping centre on March 29, 2011 in London, United Kingdom.

An Amur tiger walks across a passageway after a news conference at the Philadelphia Zoo, Wednesday, May 7, 2014, in Philadelphia. The see-through mesh pathway called Big Cat Crossing is part of a national trend called animal rotation that zoos use to enrich the experience of both creatures and guests. (Photo by Matt Slocum/AP Photo)