Burning Man 2013. The federal government issued a permit for 68,000 people from all over the world to gather at the sold out festival, which is celebrating its 27th year, to spend a week in the remote desert cut off from much of the outside world to experience art, music and the unique community that develops. (Photo by Neil Girling)

A model poses with “The Wellbeing Toilet” the winning entry from a Dyno-Rod Initiative to create a new design for the domestic toilet at Central Saint Martins on November 18, 2013 in London, England. The concept was commissioned to mark 50 years of Dyno-Rod and World Toilet Day on November 19th, 2013 The “Wellbeing Toilet” looks at the health and wellbeing aspect of getting rid of your bodily waste by being sculpted to enhance the position of your body by enabling you to squat rather than sit. (Photo by Miles Willis/Getty Images for Dyno-Rod)

A woman participates in the “Carnaval na Central” block party in Rio. (Photo by Felipe Dana/Associated Press)

Participants wrestle while riding yaks during Kyrgyz national horse games and festival near the Tulpar-Kul in the Chon Alai range, some 3500 metres (11483 feet) above sea level, Osh region, Kyrgyzstan, July 25, 2015. (Photo by Vladimir Pirogov/Reuters)

A Saddle-billed Stork is seen in Amboseli National park, Kenya, February 10, 2016. (Photo by Goran Tomasevic/Reuters)

The Zhangjiajie National Forest Park is a unique national forest park located in Zhangjiajie City in northern Hunan Province in the People's Republic of China. It is one of several national parks within the Wulingyuan Scenic Area.

Gunung Leuser National Park is a national park covering 7,927 km² in northern Sumatra, Indonesia, straddling the border of North Sumatra and Aceh provinces. The national park, named after Mount Leuser (3,381 m), protects a wide range of ecosystems. An orangutan sanctuary of Bukit Lawang is located inside the park. Together with Bukit Barisan Selatan and Kerinci Seblat national parks it forms a World Heritage Site, Tropical Rainforest Heritage of Sumatra.