Engine driver Josef Kowatsch (top L) steers a train through the NEAT Gotthard Base Tunnel during a media visit near the town of Erstfeld August 24, 2015. Crossing the Alps, the world's longest train tunnel should become operational at the end of 2016, consisting of two parallel single track tunnels, each of a length of 57 km (35 miles). (Photo by Arnd Wiegmann/Reuters)

A man dressed as a “Trapajon”, representing entities of nature, poses for a picture after taking part in the Vijanera Festival in Silio, northern Spain, Sunday, Jan. 6, 2013. The Vijanera masquerade, of pre-Roman origin, is the first carnival of the year in Europe symbolizing the triumph of good over evil and involving the participation of crowds of residents wearing different masks, animal skins and brightly colored clothing with its own complex function and symbolism and becoming the living example of the survival of archaic cults to nature. (Photo by Daniel Ochoa de Olza/AP Photo)

People dressed as zombies participate in a parade for World Zombie Day 2016 in London's West End, Britain on October 9, 2016. (Photo by Splash News and Pictures)

World Champion Matthias Dolderer of Germany flies over the Horseshoe Bend near Lake Powell in Page, United States during the transfer flight from Indianapolis to Las Vegas to prior the final stage of the Red Bull Air Race World Championship on October 12, 2016. (Photo by Predrag Vuckovic/AFP Photo)

Ireland's Philip Mulpeter, left, is kicked by Brazilian Vitor Nobrega during their welterweight mixed martial arts bout of International Pro Combat at the Estoril Casino in Estoril, near Lisbon, Portugal, Monday, January 26, 2015. Nobrega defeated Mulpeter. (Photo by Francisco Seco/AP Photo)

In this photo taken Saturday, January 24, 2015, a child makes a face while having her photo taken with the snow covered slopes of the Nanshan ski resort behind her in Beijing. As Beijing makes a final push in its bid for the 2022 Winter Olympics, Chinese President Xi Jinping says winning the bid will encourage over 300 million Chinese to take up winter sports by 2022, according to state-run Xinhua News agency. (Photo by Ng Han Guan/AP Photo)

Mahouts return home with their elephants carrying grass to feed them on the eve of the rhino census in Kaziranga National Park in Assam state, India, 24 March 2015. Kaziranga will be closed to visitors for the next two days for a census of the rhinos commencing 25 March, in a previous census in 2013 in the park the population of the Indian rhinos was 2329. (Photo by EPA/Stringer)

Revelers, covered in coloured powder, celebrate, during a Holi Run Festival in Madrid, Spain, Sunday, April 12, 2015. Thousands of revelers took part in the festival that includes a mini marathon. The festivals are fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east of India. (Photo by Andres Kudacki/AP Photo)