A visitor looks at portraits of Mao Zedong amid his statues on display at a wholesale souvenir store in Shaoshan, Hunan Province in central China, 28 April 2016. Shaoshan is the hometown of former Communist leader Mao Zedong, popularly known as Chairman Mao. Thousands of visitors descend on this small Chinese town burrowed in the hills of Central China's Hunan province to pay homage to the “Great Helmsman” everyday. It is one of the core sites of the “Red Tourism” industry, where communist party cadres and ordinary Chinese tourists alike seek to relive the experiences and rekindle the spirit of the revolutionaries. (Photo by How Hwee Young/EPA)

Royal sacred white oxen are offered food to consult the oracles during the Royal Ploughing Ceremony at the Royal Ground, Sanam Luang near the Grand Palace in Bangkok, Thailand, 09 May 2016. The ancient Brahmin rite is of great importance to the country's farmers. Thousands of farmers converge in Bangkok for the annual event, which is believed to assure a successful planting season and an abundance of crops. This year the sacred oxen ate paddy, sesame seeds, water and liquor which according to traditional soothsayers predicts that the country will have abundant food, sufficient water for agriculture as well as communication and foreign trade will improve leading to the prosperous economy. (Photo by Rungroj Yongrit/EPA)

A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

Hair artist and barber Nariko, 27, etches an image of Barcelona's Neymar on the head of customer Luiz Fernadez, 15, before the Champions League semifinal first leg soccer match between Barcelona and Bayern Munich, at his barbershop in Sao Vicente, near Santos, in Sao Paulo state May 6, 2015. Nariko, who was motivated to get into the profession by his grandfather and uncle, has been etching profiles of the famous onto the sides and backs of heads for about a year or so. (Photo by Nacho Doce/Reuters)

Women sing and dance as children gather in the background during the so-called parade of children's troops in Rostov-on-Don, southern Russia, May 14, 2015. About 500 children aged from 4 to 10, members of youth military patriotic clubs, honor guards and paratroopers took part in the event, which was organized under the guidance of Commander of Southern Military District Colonel-General Alexander Galkin and was held to honor World War Two veterans and mark the 70th anniversary of the victory over Nazi Germany, according to local media. (Photo by Eduard Korniyenko/Reuters)

Activists protest the Shell Oil Company's drilling rig Polar Pioneer which is parked at Terminal 5 at the Port of Seattle, Washington May 16, 2015. Hundreds of activists in kayaks and small boats fanned out on a Seattle bay on Saturday to protest plans by Royal Dutch Shell to resume oil exploration in the Arctic and keep two of its drilling rigs stored in the city's port. (Photo by Jason Redmond/Reuters)

A reveller sleeps on the pavement during the Sanja Matsuri festival in the Asakusa district of Tokyo May 17, 2015. The Sanja Matsuri festival attracts over about one million visitors over its duration of three days, when parties of revellers carry portable shrines through the Asakusa neighbourhood, rocking and shaking them in a belief that this intensified the powers of the deities that reside inside them. (Photo by Thomas Peter/Reuters)

Revellers attend the Victorian Picnic during the Wave and Goth festival in Leipzig, Germany, May 22, 2015. The annual festival, known in Germany as Wave-Gotik Treffen (WGT), features over 100 bands and artists in venues all over the city playing Gothic rock and other styles of the dark wave music subculture. One of the biggest of its kind, the event attracts a regular audience of up to 20,000, the organisers said. (Photo by Hannibal Hanschke/Reuters)