Seljalandsfoss waterfall, located in Iceland. Seljalandsfoss is one of the most famous waterfalls of Iceland. This waterfall of the river Seljalandsá drops 60 metres (200 ft) over the cliffs of the former coastline. It's possible to go behind the waterfall. (Photo by HotSpot Media)

A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

A guard stands at Dityatki checkpoint, marking a 30 km (18-mile) zone around the Chernobyl nuclear power plant April 23, 2013. Ukraine will mark the 27th anniversary of the Chernobyl disaster, the world's worst civil nuclear accident, on April 26. (Photo by Gleb Garanich/Reuters)

“Old Mursi woman”. Old woman by the huts of her village. Location: Marenke, Omo valley, Ethiopia. (Photo and caption by Jorge Fernandez/National Geographic Traveler Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

A copy of part of the Dead Sea Scrolls is displayed at the “Dead Sea Scrolls: Life and Faith in Biblical Times” exhibition at Discovery Times Square on December 16, 2011 in New York City. (Photo by Spencer Platt/Getty Images)

A woman dressed in an alien space suit carries an American flag and a sign that reads “Women's Revolution 1971” as she marches in a Women's Liberation demonstration on Fifth Avenue in New York, August 26, 1971. (Photo by Marty Lederhandler/AP Photo)

Green algae sits on a beach in Kuwait City, Kuwait, 28 February 2017. The formation of green algae is a normal phenomenon that occurs every year at the shores of Kuwait. (Photo by Raed Qutena/EPA)

In this February 4, 2016 picture a masked participant of the traditional carnival parade poses in the streets of the village of Kippel in the Loetschental valley, southwestern part of Switzerland. During this sinister carnival, participants wearing wooden masks and animal furs, crowd the streets of the villages to scare the people. (Photo by Dominic Steinmann/Keystone via AP Photo)