In this photo taken on July 19, 2014, a man looks at an excavation as an A.R.M.H., Association for the Recovery of Historical Memory, volunteer digs on the search for the body of Perfecto de Dios, in a hidden grave in Chaherrero, Spain. Across Spain, volunteer teams of archeologists, anthropologists and forensic scientists head out every year on expeditions to dig for suspected mass graves – a legacy of Spain's fascist past during the time of General Francisco Franco. (Photo by Daniel Ochoa de Olza/AP Photo)

In this December 19, 2014 photo, a man stands beside his 1957 Chevrolet Bel-Air car in Havana, Cuba. U.S. car sales have been banned in Cuba since 1959. Cubans have been have been forced to patch together Fords, Chevrolets and Chryslers that date back to before Fidel Castro's revolution which can make it appear like the country is stuck in a 1950s time warp. Since the Communist economic system isn't likely to change soon, many of those cars will have to stay on the road for years. (Photo by Desmond Boylan/AP Photo)

Antek Marciniec holds onto a slackline after falling off as he highlines between two cliffs at Diamond Bay on December 21, 2014 in Sydney, Australia. Slacklining is a balance sport in which participants walk on a flat nylon webbing anchored between two points with the tension adjusted to allow for slack, providing an experience similiar to that of walking on a trapmoline. Highlining is a style of slacklining where the two anchor points are set up with significant elevation from the ground or water. (Photo by Cameron Spencer/Getty Images)

A reveller dressed up as Austrian drag queen and 2014 Eurovision song contest winner Conchita Wurst takes part in New Year's celebrations in Coin, near Malaga, southern Spain, early January 1, 2015. Villagers and revellers dressed up in funny costumes to take part in the New Year's celebration. (Photo by Jon Nazca/Reuters)

Members of South Korean girl group Gfriend rehearse in Seoul December 23, 2014. Thousands of Korean children dream of becoming household names like rapper Psy, whose 2012 “Gangnam Style” video was a global YouTube hit, often putting up with punishing schedules in the hope of one day making it big in the music industry. A recent survey of pre-teens showed that 21 percent of respondents wanted to be K-pop (Korean pop) stars when they grow up, the most popular career choice. (Photo by Kim Hong-Ji/Reuters)

A Palestinian youth jumps with a sword as he demonstrates his ninja-style skills for the photographer in front of the ruins of buildings, that were destroyed in 2014 war, in the northern Gaza Strip January 29, 2016. The youths, who have been receiving martial arts training at local clubs in Gaza for the past two years, decided to form a team to hold regular shows in the hope that the publicity generated will eventually lead to them being invited to participate in international contests. (Photo by Mohammed Salem/Reuters)

Gisele Marie, a Muslim woman and professional heavy metal musician, plays her Gibson Flying V electric guitar during a concert in Sao Paulo December 16, 2014. Based in Sao Paulo, Marie, 42, is the granddaughter of German Catholics, and converted to Islam several months after her father passed away in 2009. Marie, who wears the Burka, has been fronting her brothers' heavy metal band “Spectrus” since 2012. (Photo by Nacho Doce/Reuters)

Members of the media film as a ranger performs a post mortem on the carcass of a rhino after it was killed for its horn by poachers at the Kruger national park in Mpumalanga province August 27, 2014. Rhino poachers in South Africa now risk giving themselves away when they shoot thanks to a high-tech, gunfire-detection system being piloted in the country's flagship Kruger National Park. The stakes are high, for rhinos are being slain in escalating numbers for their prized horns, alarming both conservationists and the government since wildlife in South Africa is an important tourist draw. (Photo by Siphiwe Sibeko/Reuters)