Dhruva Aliman does a back somersault as he dismounts from a slackline on the beach at Santa Monica, California on October 19, 2014. Slackline is a balance sport where a line of webbing is adjusted at different levels of tension between two anchor points and participants (called slackers) perform tricks and stunts including somersaults. (Photo by Mark Ralston/AFP Photo)

West Berliners crowd in front of the Berlin Wall as they watch East German border guards demolish a section of the wall on November 11, 1989. (Photo by Gerard Malie/AFP Photo)

Men stroll past roadside vendors as a painted truck makes its way through the busy street in Kabul, Afghanistan, November, 1961. (Photo by Henry S. Bradsher/AP Photo via The Atlantic)

“The Amazon river has a newly discovered source. Completed last year and led by West Hansen and documented by award-winning freelance photographer Erich Schlegel, this is the first expedition to paddle from the furthest source of the earth's largest river to the ocean”. – zReportage. Photo: August 19, 2012 – Alpamarca, Peru – Amazon Express white water members Juan Antonio De Ugarte, of Peru, Rafael Ortiz, of Mexico, West Hansen, of the U.S., and Tino Specht, of the U.S., paddle down the Rio Gashan after leaving Lago Acucocha. Lago Acucocha is possibly the dry season source of the Amazon River. (Photo by Erich Schlegel/zReportage via ZUMA Press)

A frog sits on a leaf and instead of seeing a reflection of itself in the water below, it sees a snail, attached to the bottom of the leaf, in a fish tank in Vietnam. (Photo by Duong Quoc Dinh/Solent Ne/SIPA Press)

Performer Zhang Yashu from a Chinese ballet company perform during a photo shoot in front of the Australia's iconic landmarks Opera House (L) and Habour Bridge in Sydney on February 17, 2014. One of China's celebrated dance campanies is bringing one of the country's biggest ballet production to Australia for a series of performances in Sydney and Melbourne. (Photo by Saeed Khan/AFP Photo)

Police investigators inspect the bodies of two men lying on a sidewalk, who police said were killed after a drug “Shabu” (Methamphetamine Chloride) buy-bust operation in Quezon city, Metro Manila Philippines, October 9, 2016. (Photo by Ezra Acayan/Reuters)