Dancers perform during the Sambodromo do Brasil jungle party in the Cave stage, Elrow Town at Queen Elizabeth Olympic Park on August 18, 2018 in London, England. (Photo by Ollie Millington/Redferns)

Internally displaced Syrian children stand at the entrance of their makeshift shelter that is an underground cave in Om al-Seer, southern Idlib countryside, Syria December 26, 2015. (Photo by Khalil Ashawi/Reuters)

A woman works at a factory producing clay pots at Phu Lang pottery village in Bac Ninh province, Vietnam, May 14, 2015. The village is part of an old pottery triangle in northern Vietnam which includes Bat Trang and Tho Ha, and has been producing pottery since the 13th century, according to local media. (Photo by Reuters/Kham)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

“After an afternoon of hiking and exploring the caves of Rhossili Bay, West Glamorgan, we caught the sun breaking through the clouds”. (Photo by Megan Warren-Davis/The Guardian)

Visitors are seen with giraffes on a bus at Safari Park in Kanchanaburi Province, Thailand, January 19, 2020. Kanchanaburi in western Thailand an area known for its waterfalls and caves. (Photo by Rachen Sageamsak/Xinhua News Agency/Eyevine)

South Asian countries in terms of total contribution of travel and tourism to GDP. #6. Vietnam, Total GDP: USD 202.6 billion (2016). Contribution of Travel and Tourism to GDP: 9.1% . Here: A boat in the Thu Bon River, Hoi An, Vietnam. (Photo by Domingo Leiva/Getty Images)

Young women walk through the cave of Saint George during Ashenda festival, at Saint George Church, in Lalibela, Ethiopia, on August 22, 2022. (Photo by Amanuel Sileshi/AFP Photo)