People walk throw the Damascus gate during the Jerusalem Festival of Lights on June 15, 2011 at Jerusalem's Old City, Israel. The festival opened on Wednesday night and will run for a week in the Old City of Jerusalem, hosting Israeli and international artists and creators who will display their installations throughout the week. (Photo by Uriel Sinai/Getty Images)

Commuters use a plastic sheet to take shelter from rain as they ride through a waterlogged road in Ahmedabad, India, July 27, 2016. (Photo by Amit Dave/Reuters)

A family poses for a picture in front of the carcasses of sacrificed buffalos a day after the sacrificial ceremony of the “Gadhimai Mela” festival held in Bariyapur November 29, 2014. Sword-wielding Hindu devotees in Nepal began slaughtering thousands of animals and birds in a ritual sacrifice on Friday, ignoring calls by animal rights activists to halt what they described as the world's largest such exercise. (Photo by Navesh Chitrakar/Reuters)

Two women jump into a frozen pond as they compete in the Polar Plunge at Frozen Dead Guy Days in Nederland, Colorado March 14, 2015. The winter festival in the small mountain town commemorates the 1994 discovery of the corpse of Bredo Morstol, which is now housed in a shed on dry ice above the town. (Photo by Rick Wilking/Reuters)

A bulldog dressed as Marilyn Monroe poses for a photograph during the annual Tompkins Square Halloween Dog Parade in the Manhattan borough of New York City, October 24, 2015. (Photo by Stephanie Keith/Reuters)

An Afghan woman walks along a street covered with snow on the outskirts of Kabul, Afghanistan February 7, 2017. (Photo by Omar Sobhani/Reuters)

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)