Walkers cross the river Waalbrug during the first day of the 98th annual four-days walking event, the “Vierdaagse” in Nijmegen, Netherlands, July 15, 2014. The “Nijmeegse Vierdaagse” is an annual public four-day field march which is held since 1909 in the third week of July. (Photo by Erik van 't Wout/EPA)

Patarawan fixes her boots as her parrot, Sim sits on her head as she goes shopping for dinner at a busy flooded market near the Chao Phraya river October 27, 2011 in Bangkok, Thailand. Hundreds of factories closed in the central Thai province of Ayutthaya and Nonthaburi as the flood waters began to reach Bangkok. Around 350 people have died in flood-related incidents since late July according to the Department of Disaster Prevention and Mitigation, with Thailand experiencing the worst flooding in 50 years. (Photo by Paula Bronstein/Getty Images)

Over 1000 New Year revellers, many in fancy dress, braved freezing conditions in the River Forth in front of the Forth Rail Bridge during the annual Loony Dook Swim on January 1, 2012 in South Queensferry, Scotland. Thousands of people gathered last night to see in the New Year at Hogmanay celebrations in towns and cities across Scotland. (Photo by Jeff J. Mitchell/Getty Images)

A gaggle of goslings huddle together under the protective wing of a parent along the bank of the Deschutes River as a heavy downpour passes through Bend, Oregon, late Wednesday, April, 20, 2106 afternoon. (Photo by Ryan Brennecke/The Bulletin via AP Photo)

A boy catches a trout while ice fishing on a frozen river during a fishing contest in Hwacheon, South Korea, Saturday, January 14, 2017. The contest is part of an annual ice festival which draws over 1,000,000 visitors every year. (Photo by /Ahn Young-joon/AP Phot)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A young girl sells balloons by the Yamuna River as devotees carrying idols of the Hindu god Ganesh, the deity of prosperity, immerse the idol on the last day of the ten-day-long Ganesh Chaturthi festival in Delhi, India, September 15, 2016. (Photo by Cathal McNaughton/Reuters)

Peter Ver Ploeg carries Virginia Petrovek through the mud pit during the North American Wife Carrying Championship, Saturday, October 8, 2016, at the Sunday River Ski Resort in Newry, Maine. (Photo by Robert F. Bukaty/AP Photo)