In this October 29, 2013 photo, Daniel smokes marijuana inside his apartment where he uses a hydroponics system to grow his weed in Mexico City. “I'm not a narco, dude. I just like to smoke”, said Daniel, who spoke on condition that his last name not be used because, he said, his home-grow operation is "super-illegal" despite being for personal use only. (Photo by Eduardo Verdugo/AP Photo)

Contestants for the Miss World grand final perform in colourful costumes during a dress rehearsal in Sanya, Hainan province, China, 18 December 2015. (Photo by How Hwee Young/EPA)

Children surround a man, left, that fell down while walking on a street suspected of having contracted the Ebola virus in the city of Monrovia, Liberia, Tuesday, August 19, 2014. The World Health Organization says the outbreak has killed more than 1,200 people, while authorities struggle to contain its spread and treat the sick. (Photo by Abbas Dulleh/AP Photo)

“Kilauea Rules”. The most extreme place we put ours kayakers to paddle till now. Photo location: Big Island, Hawaii. (Photo and caption by Alexandre Socci/National Geographic Photo Contest)

Russian opposition leader, Alexei Navalny (C), reacts as the court delivers the verdict in his trial, in the city of Kirov, Russia, 18 July 2013. Alexei Navalny was sentenced to five years in jail for theft on Thursday, an unexpectedly tough punishment which supporters said proved President Vladimir Putin was a dictator ruling by repression. (Photo by Valentina Svistunova/EPA)

A large Pacific sideband snail slowly crosses a rain wet road in rural Douglas County, Oregon near Elkton on Sunday, December 2, 2012. The moisture loving snail should be very content with the recent heavy rains in southwestern Oregon and northern California. (Photo by Robin Loznak)

The Mike O'Callaghan–Pat Tillman Memorial Bridge is an arch bridge in the United States that spans the Colorado River between the states of Arizona and Nevada. The bridge is located within the Lake Mead National Recreation Area approximately 30 miles (48 km) southeast of Las Vegas, Nevada, and carries U.S. Route 93 over the Colorado River.

Pakistani laborers transport the front portion of a vehicle using a handcart at a road in Peshawar, Pakistan, Monday, August 3, 2015. (Photo by Mohammad Sajjad/AP Photo)