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)

The bare feet of a devotee are pictured as she takes a dip at the Bagmati River during the “Bol Bom” (Say Shiva) pilgrimage in Kathmandu July 21, 2014. The faithful, chanting the name of Lord Shiva, run about 15 km (9 miles) barefooted toward Pashupatinath temple seeking good health, wealth and happiness. (Photo by Navesh Chitrakar/Reuters)

This restroom on the rubbly flanks of Jonsknuten in Norway looks up at the peak of the 904m mountain. Yu have to leave the door open to enjoy the view but the chances of being disturbed are minimal. (Photo by Olaf Menz/Lonely Planet)

Pamukkale, Turkey, is home to these terrace pools, formed by the build-up of carbonate mineral from the warm water flowing from the thermal springs above. (Photo by Image Courtesy of Jennifer Hayes/Getty Images)

Wildlife photographer Danté Fenolio has headed into areas untouched by sunlight – deep seas, caves and underground – and found creatures that are exploding with colour. Here: The golden harlequin toad has vanished from the wild, and only a small number live on in captivity. A fungus caused them, and many other amphibians, to die out in their home in Central America. (Photo by Danté Fenolio/The Guardian/Johns Hopkins University Press)

A general view of Uluru is seen as it rains on November 28, 2013 in Uluru-Kata Tjuta National Park, Australia. Uluru/ Ayers Rock is a large sandstone formation situated in central Australia approximately 335km from Alice Springs. The site and its surrounding area is scared to the Anangu people, the Indigenous people of this area and is visited by over 250,000 people each year. (Photo by Mark Kolbe/Getty Images)

The Rafflesia Arnoldi flower (Amarphophallus titanum) which has been cultivated is seen in Palupuah Village, Agam District, West Sumatra, Indonesia, on April 13, 2022. The West Sumatera Nature Conservation Agency (BKSDA) estimates around seven Rafflesia Arnoldi flowers will bloom in Palupuah Village this year. (Photo by Adi Prima/Anadolu Agency via Getty Images)

Sunrise over the River Thames and Tower Bridge in London today morning on January 28, 2024. It has been forecast that Sahara dust will be in the atmosphere. (Photo by Alister Gooding/Picture Exclusive)