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)

In this photo taken Sunday, May 6, 2012, Denis Lutskevich, left, is detained by police during an opposition rally in Bolotnaya Square in Moscow. The former naval cadet and first-year student, 21-year-old Lutskevich was attending his first protest when he was detained, and is still in prison Monday May 6, 2013, on the first year anniversary of the protest. (Photo by Pavel Golovkin/AP Photo)

Paramedics carry an injured woman out from a subway station after a rush-hour subway train derailment, to be transported by a medical helicopter in Moscow, Russia, on Tuesday, July 15, 2014. A rush-hour subway train derailed in Moscow Tuesday, killing 20 people and injuring at least 150, emergency officials said. Several cars left the track in the tunnel after a power surge triggered an alarm, which caused the train to stop abruptly. (Photo by Ivan Sekretarev/AP Photo)

The hull on a boat that carried Rohingya migrants for three months is seen at Langkawi island, in the Malaysia's northern state of Kedah, Malaysia, May 12, 2015. Thailand and Malaysia may set up camps and detention centers to shelter hundreds of refugees arriving on their shores, officials said on Tuesday, as a leading inter-governmental agency said about 7,000 boat people were still adrift in the Bay of Bengal. (Photo by Olivia Harris/Reuters)

Chase Elliott (9) makes a pit stop during the NASCAR Xfinity series auto race at Chicagoland Speedway, Sunday, June 21, 2015, in Joliet, Ill. (AP Photo/Nam Y. Huh)

Abandoned cars are seen around a cross in the village of Tbeti near Tskhinvali, the capital of the breakaway region of South Ossetia, Georgia, July 4, 2015. President Vladimir Putin signed a treaty with Georgia's rebel South Ossetia region on March 18 that almost completely integrates it with Russia, alarming Georgia and the West a year after Moscow took over Crimea. Russia won a five-day war with Georgia in 2008 over the fate of South Ossetia and another rebel region, Abkhazia. It formally recognizes both regions as independent states and signed a similar treaty with Abkhazia last year. (Photo by Kazbek Basaev/Reuters)

Flames from the Jerusalem Fire erupt in Lake County, California August 12, 2015. The wildfire running rampant through drought-parched vegetation in northern California grew by several thousand acres overnight into Wednesday, as firefighters worked to stop the flames from spreading toward communities. (Photo by Robert Galbraith/Reuters)

People and sea-gulls bathe in the sea as the sun goes up with red colors in Stralsund close to the baltic sea island of Rügen, on early November 23, 2016. (Photo by Stefan Sauer/AFP Photo/DPA)