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)
Yakutsk, with a population of around 270,000, holds its own title: that of the coldest city on Earth. Here: Frost-encrusted house in the city centre. (Photo by Amos Chapple/Courtesy Images/RFE/RL)
A plane flies past the moon in west London on Monday, January 17, 2022. The first full moon – the Wolf moon according to native north Americans – of 2022. (Photo by Victoria Jones/PA Images via Getty Images)
The strength of a weaver ant carrying fruit in Indonesia in the last decade of August 2024 is equivalent to the average man or woman picking up a minibus. (Photo by Ridho Arifuddin/Solent News)
Mud-covered tourists pretend to be trapped inside a mud prison at the Daecheon Beach Mud Plaza in the city of Boryeong on South Korea's west coast, July 17, as they take part in the Boryeong Mud Festival, which opened that day and runs through July 26. Boryeong mud is rich in natural mineral component and is considered to prevent skin aging. (Photo by EPA/Yonhap)
A man watches the approaching flames as the Springs fire continues to grow near Camarillo, California, on May 3, 2013. The wildfire has spread to more than 18,000 acres on day two and is 20 percent contained. (Photo by David McNew)
World medieval jousting champion Rod Walker poses before next month’s St Ives Medieval Faire, the only solid wood lance joust tournament in the southern hemisphere in Sydney, Australia on August 26, 2016. (Photo by Dan Himbrechts/AAP)