A swimmer reacts after finishing his competition in a pool carved into thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province January 5, 2015. The swimming competition was held on the official launch day of the Harbin International Ice and Snow Sculpture Festival. (Photo by Kim Kyung-Hoon/Reuters)

A woman rides the world's longest urban zip line, with a speed of up to 80 kilometers per hour on a one kilometer run from 170 meter to ground level, in the Marina district of Dubai, United Arab Emirates, Tuesday, December 5, 2017. (Photo by Kamran Jebreili/AP Photo)

A member of the Tinstix of Dynamite aerobatics team flies in front of a wall of fire during the Australian International Airshow in Melbourne on March 5, 2017. The annual event sees 180,000 visitors over the 3-day public event held at the Avalon Airfield some 80kms south-west of Melbourne. (Photo by Mal Fairclough/AFP Photo)

Iranian women perform as they train Far East Fighting Arts to be able to defend themselves, at the Jughin castle which is located 40 km's far from Tehran, Iran on June 5, 2017. (Photo by Fatemeh Bahrami/Anadolu Agency/Getty Images)

Paris authorities began draining the Canal Saint-Martin, a popular waterway that attracts tourists and revelers in the French capital's trendy northeastern 10th arrondissement, for the first time in 14 years, Paris, January 5, 2016. (Photo by Christophe Geyres/SIPA Press/Newscom)

Revellers take part in an annual block party before Carnival in downtown Rio de Janeiro, Brazil, January 16, 2016. The Rio de Janeiro Carnival will be held from February 5 to February 9. (Photo by Pilar Olivares/Reuters)

A woman holds a hedgehog at the Harry hedgehog cafe in Tokyo, Japan, April 5, 2016. In a new animal-themed cafe, 20 to 30 hedgehogs of different breeds scrabble and snooze in glass tanks in Tokyo's Roppongi entertainment district. Customers have been queuing to play with the prickly mammals, which have long been sold in Japan as pets. The cafe's name Harry alludes to the Japanese word for hedgehog, harinezumi. (Photo by Thomas Peter/Reuters)

These pictures show the beautiful ruins of abandoned temples. The incredible shots, taken at temples in Angkor, Cambodia, show the striking yet haunting temples as they crumble to ruins. While they may have lost some of their former glory, the stunning temples show the beauty of the Cambodian landscape through the historic architecture. Here: Sun rises over the 5 towers of Angkor. (Photo by Alex Teuscher/Caters News)