Asia Sawicka as Anastasia IV poses for a photograph prior to a rehearsal of the Circus of Horrors' latest show Voodoo, ahead of Halloween, at the Wookey Hole Caves Theatre near Wells on October 19, 2017 in Somerset, England. (Photo by Matt Cardy/Getty Images)

National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)

Mother and son in disguise attend a Halloween celebration at Taipei Children's Amusement Park in Taipei, Taiwan, Sunday, October 29, 2023. (Photo by Chiang Ying-ying/AP Photo)

Actor and former California Governor Arnold Schwarzenegger (R) and his son Patrick Schwarzenegger (L) attend “Arnold Classic Europe” 2011 Party at “Jardines Cecilio Rodriguez” on October 7, 2011 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)

A Malaysian Hindu devotee (C) reacts in a state of trance as she walks towards the Batu caves temple during the Thaipusam festival celebrations in Kuala Lumpur on January 24, 2016. More than a million Hindus celebrate the festival of “Thaipusam” at temples across the country. (Photo by Manan Vatsyayana/AFP Photo)

A hat and boots belonging to a volunteer with the Israeli Antique Authority are seen inside the Cave of the Skulls, an excavation site in the Judean Desert near the Dead Sea, Israel June 1, 2016. A team of volunteers and archaeologists are searching for remains of The Dead Sea Scrolls, one of the oldest known Hebrew texts, in a national bid, initiated by the Israel Antiquities Authority (IAA), to prevent the robbery of such important artefacts and once found to hand them over to the state for preservation. (Photo by Ronen Zvulun/Reuters)

“Winter Climbing from inside Ben Nevis”. The view from inside the mountain, as a winter climber passes through the cave on Minus Three gully. Photo location: Ben Nevis, Fort William, Scotland. (Photo and caption by Daniel Wildey/National Geographic Photo Contest)

Ice swimmer Klaudia prepares to swim in a filled up water kettle in an ice cave inside the Nature Ice Palace, with a hight of 3,250 meters (10,663 feet) above sea level, at Hintertux Glacier near Hintertux, some 480 kilometers (298 miles) western of Vienna, Austria, 28 July 2018. (Photo by Christian Bruna/EPA/EFE)