On the western side of Mount Hood lies the longest glacier cave system in the contiguous United States. In 2012, these caves were mapped to a combined length of 7,166.8 feet by cave explorers Brent McGregor and Eddy Cartaya. Currently, the total passage length is hundreds of feet less. Glaciers are frozen rivers; they are always moving and changing... (Photo and caption by Josh Hydeman)

Vultures gather to eat waste in Bica beach, on the banks of the Guanabara Bay, with the Sugar Loaf mountain in background, 500 days ahead the Rio 2016 Olympic Games in Rio de Janeiro March 24, 2015. As part of its Olympic bid, Rio promised to clean up 80 percent of the bay for the games. But local government officials have already admitted that a cleanup by 2016 is not achievable. Despite millions of dollars of investment over the years, the bay still stinks of sewage. Sailors who visited the city for test events complained of a floating sofa and a dead dog in the water. (Photo by Ricardo Moraes/Reuters)

From Manhattan and Brooklyn's trendiest neighborhoods to the far-flung edges of theouter boroughs, Will Ellis has spent the last three years photographing and researching the lost and lonely corners of the United States' most populous city. His photo book Abandoned NYC is packed with 150 color images of sixteen of New York's most beautiful and mysterious abandoned spaces, paired with detailed essays on the fascinating history of these forgotten sites. Here: Letchworth Village is located just an hour's drive from NYC in Thiells, NY. It was founded in 1912 to house the city's developmentally disabled as a ”state institution for the epileptic and feeble-minded”. (Photo by Will Ellis)

A woman poses next to two mailboxes along a street in Taipei on August 11, 2015 that were reportedly bent by strong winds brought by Typhoon Soudelor over the weekend. The two iron mailboxes have become an unlikely attraction, drawing thousands of snap-happy visitors and have even become a backdrop to a wedding photo shoot. The typhoon, which hit in the early hours of August 8 and was billed as the most powerful typhoon this year, uprooted trees, brought down electricity poles, knocking out power to a record 4.3 million households, while leaving eight dead and four missing. (Photo by Benjamin Yeh/AFP Photo)

Indian artist Sudarsan Pattnaik works on a sand sculpture depicting drowned Syrian boy Aylan Kurdi at Puri beach, some 65 kilometers away from Bhubaneswar, on September 4, 2015. Charities helping refugees saw a surge in donations on September 4 across Europe as people shocked by the heart-rending images of a drowned Syrian boy on a Turkish beach dug deep to help out. The photos of the lifeless body of three-year-old Aylan Kurdi, lying on a beach in Bodrum, Turkey, have triggered a wave of emotion across the continent, despite deep divisions among European governments on how to deal with the crisis. (Photo by Asit Kumar/AFP Photo)

In this Tuesday, July 14, 2015, photo, Phoe Thaw, center, a member of the White New Blood lethwei fighters club, a Myanmar traditional martial-arts club which practices a rough form of kickboxing, stretches during a practice session in their gym on a street in Oakalarpa, north of Yangon, Myanmar. Three of the club's members competed this summer on a stage a world away from the street gym: a mixed-martial-arts “One Championship” event broadcast globally on cable television networks, where fighters could receive $1,000 for each fight, according to coach Myint Zaw who started the traditional fighters' club 15 years ago. (Photo by Gemunu Amarasinghe/AP Photo)

Using his camera skills, Marc meters the background sky in order to achieve the beautiful black silhouettes of the wildlife, Africa, 2010-2016. (Photo by Marc Mol/Barcroft Images)

A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)