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)

Actors perform the living Nativity biblical scenes in Postojna cave in Postojna, Slovenia, December 22, 2015. (Photo by Srdjan Zivulovic/Reuters)

These stunning photographs really do show a land of fire and ice! The frozen landscape of the Olkhon Islands, Russia, appears to be ablaze in some of these pictures as the icy sheets of the glaciers reflect the early morning suns rays. (Photo by Vladimir Ryabkov/Caters News Agency)

A member of a comparsa, a Uruguayan carnival group, dances during the Llamadas parade in Montevideo February 5, 2015. Thousands of people crowd the capital's Barrio Sur as costumed drummers and dancers kick off the street fiesta known as Llamadas which has traditional Afro-Uruguayan roots. The fiesta, also known in Spanish as “The Calls”, started during the colonial period as a slave parade on the city streets. (Photo by Andres Stapff/Reuters)

The Mercedes Simplex concept car, inspired on its original 1903 Mercedes-Simplex, is displayed at the LA Auto Show in Los Angeles, California, U.S. November 20, 2019. (Photo by Lucy Nicholson/Reuters)

Girls watch a procession during the “Fiesta de las Palancas” celebration to ask for blessings and abundance during the new year in Panchimalco, El Salvador, January 5, 2017. (Photo by Jose Cabezas/Reuters)

“Maya” girl Ines de la Paloma, 9, (L), sits with her friend Nuria Sanchez Caballero, 6, at an altar during “Las Mayas” festivity in Madrid, Spain, May 8, 2016. “Las Mayas” festival is held annually at the beginning of May to celebrate the awakening of nature in Spring. Young girls are chosen to become “Mayas” and sit at altars decorated with flowers so that people can admire them. (Photo by Susana Vera/Reuters)

A 1964 Amphicar driven by James Spear of Henderson, Nevada is shown on the boat launch after a trip to Hoover Dam during the first Las Vegas Amphicar Swim-in at Lake Mead near Las Vegas, Nevada October 9, 2015. The German-made Amphicar was produced from 1961-1968. (Photo by Steve Marcus/Reuters)