People take a selfie at the abandoned former Soviet R12 nuclear missile launch site in Zeltini, Latvia, July 22, 2016. Hidden in the forests of Aluksne, near Latvia's north-eastern border with Russia, the remains of a former Soviet nuclear missile base are a magnet for tourists now rather than a top-secret site manned by soldiers. (Photo by Ints Kalnins/Reuters)

A Christian pilgrim prays during her visit to the baptismal site known as Qasr el-Yahud on the banks of the Jordan River near the West Bank city of Jericho April 9, 2015. A day ahead of Orthodox Good Friday, the Easter period draws many Christian tourists to visit well-known religious sites, including Qasr el-Yahud, where it is believed John the Baptist baptised Jesus. (Photo by Amir Cohen/Reuters)

A muslim pilgrim walks through the site where dead bodies are gathered in Mina, Saudi Arabia during the annual hajj pilgrimage on Thursday, September 24, 2015. Hundreds were killed and injured, Saudi authorities said. The crush happened in Mina, a large valley about five kilometers (three miles) from the holy city of Mecca that has been the site of hajj stampedes in years past. (Photo by AP Photo)

On August 18, 2012 the infection spreads again as the undead hordes shamble through Vancouver in search of brains. The annual Zombie Walk has been going on for years and each year gets bigger and bigger. (Photo by Gord Gallagher)

Ace Wu searches the deep to photograph stunning underwater creatures. Against their predominantly black backdrops, Wu’s breathtaking subjects glow with sublime vibrancy. In one, a fearsome fish glares at the camera with rows of sharp teeth showing, while in another, a translucent octopus looks like an extraterrestrial. Here: Wunderpus larva. (Photo by Ace Wu/Caters News Agency)

The Facebook website is displayed on a laptop computer on May 9, 2011 in San Anselmo, California. An investigation by The Pew Research Center found that Facebook has become a player in the news industry as the popular social media site is driving an increasing amount of traffic to news web sites. (Photo Illustration by Justin Sullivan/Getty Images)

A Pakistani labourer carries bricks on his back at a construction site at a residential area in Islamabad on March 29, 2017. (Photo by Aamir Qureshi/AFP Photo)

A partial solar eclipse is seen as a labourer works at a construction site in Phnom Penh, Cambodia, March 9, 2016. (Photo by Samrang Pring/Reuters)