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)

“I started photography in June 2009. At the time, I was searching for a way to express both the rigorous scientist and the creative artist in me. There are few hobbies that let these two approaches work together, so I really was enthusiastic about it: I am now spending all my free time studying various techniques, contemplating others' fantastic work, and of course, making pictures”. – Christophe Kiciak. Photo: “The Hero”. (Photo by Christophe Kiciak)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

China’s new tallest building has received unexpected publicity thanks to Russian free climbers Vadim Makhorov and Vitaly Raskalov. The pair took two hours to climb 650 metres up the unfinished Shanghai Tower. They did not use safety equipment on their ascent to the top of a crane attached to the tower, from where they took these extraordinary pictures of Shanghai. Photo: Vitaly Raskalov's feet dangle from the top of the Shanghai Tower, high above the Shanghai World Financial Centre. (Photo by Vitaly Raskalov/Caters News Agency)

Armed with only paper, graphite and coloured pencils – plus his vivid imagination – the artist creates remarkable drawings that leap from the page when photographed. The 32-year-old, from Alkmaar in Holland, began experimenting with anamorphic 3D drawing five years ago. Photo: Ramon Bruin’s 3D illustration of two twins drawing each other. (Photo by Ramon Bruin/Medavia)

“Diver in Magic Kingdom”. Green Lake (Grüner See) is located Tragöss Austria. In spring snowmelt raises the lake level about 10 meters. This phenomenon, which lasts only a few weeks covering the hiking trails, meadows, trees. The result is magical to watch diving landscapes. Photo location: Grüner See at Tragöss, Austria. (Photo and caption by Marc Henauer/National Geographic Photo Contest)

Visitors walk past the fully equipped dining table inside the “Crazy House”, which is completely built upside-down, in the village of Affoldern near the Edersee lake, May 7, 2014. Three friends came up with the idea to build the tourist attraction, which cost about 200,000 euros and took some six weeks to complete. (Photo by Kai Pfaffenbach/Reuters)

A picture taken on March 16, 2017 shows women dressed up as mermaids posing by a pool at a mermaid training school in Moscow. Russian women who have dreamt of becoming a mermaid since their youngest years, start turning their fantasies into reality with a new type of fitness – mermaid swimming. (Photo by Natalia Kolesnikova/AFP Photo)