The adventurous explorers have snapped themselves in shark-infested waters, at the side of an active volcano, atop a Hong Kong skyscraper surrounded by toxic smog, and even perched on the top of iconic Rio statue of Christ the Redeemer. Here: Ervin Punkar using a selfie stick to take a photo from the very top of the 600ft TV tower in Tartu, Estonia. (Photo by Ervin Punkar/Caters News Agency)

Martin Rietze is a “volcano-chaser”, a particular breed of photographer who takes big risks for big shots. He was able to capture destructive and beautiful forces of nature at work on a trip to Japan in February 2013. His photos show the Sakurajima Volcano, an active volcanic who's record-breaking 1914 eruption sent lava flows across the island. (Photo by Martin Rietze/Guzelian)

Men work at a makeshift oil refinery site in Marchmarin town, southern countryside of Idlib, Syria December 16, 2015. The refinery site, owned by Yousef Ayoub, 34, has been active for 4 months. Ayoub says that he gets the crude oil from Islamic State-controlled areas in Deir al-Zor province and Iraq. The price for a barrel of crude oil varies and is controlled by the Islamic State, but it is currently at $44 dollars per barrel, he said. (Photo by Khalil Ashawi/Reuters)

A Hindu worshipper throws vegetables into the crater as offerings during the Kasada Festival at Mount Bromo in Probolinggo, Indonesia's East Java province, August 1, 2015. Every year people gather for the annual festival where offerings of rice, fruit, vegetables, livestock or money are made to Hindu gods at the active volcano to ask for blessings and assure a bountiful harvest. (Photo by Reuters/Beawiharta)

Voodoo pilgrims bathe in a waterfall believed to have purifying powers during the annual celebration in Saut d' Eau, Haiti, Saturday, July 16, 2016. Annually, the falls are the site of a large, important religious pilgrimage, during the festival of Our Lady of Carmel, from July 14–16. A Eucharistic rite is held during the festival, as well as various vodou rituals, but the penultimate devotional activity is bathing in the waters of the falls, and asking favors of the Virgin or Erzulie. After bathing, voodoo pilgrims throw away the dresses they wore to the site, and don new clothes for good luck. (Photo by Dieu Nalio Chery/AP Photo)

Nine years ago, Tom Carter traveled from San Francisco to China, responding to a job posting that turned out to be a scam. He managed to find another job as a teacher, and saved enough money to embark on a 56,000 km trip through all of China's 33 provinces that lasted two years. Carrying a camera – just a a 4-megapixel point-and-shoot – Carter captured some amazing images of the widely varying landscape, people, and architecture across the nation. Photo: Buddhist pilgrim family from Sichuan. (Photo by Tom Carter via The Atlantic)

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.