Participants take part in the 14th annual “No Trousers Tube Ride” event on the London Underground on January 12, 2025. The event, staged by Improv Everywhere, takes place every January in New York City and has since expanded internationally. What began as a small prank with just seven participants has grown into a global celebration of silliness, with dozens of cities, including London, joining in each year. (Photo by Guy Bell/Alamy Live News)

Sam Warren climbs in to a prototype combat vehicle during the PrepperCon expo Friday, April 24, 2015, in Sandy, Utah. Hundreds of survivalists and “preppers” are gathering in the Salt Lake City suburb of Sandy for the first annual PrepperCon, featuring demonstrations of underground bunkers, food storage, and armored vehicles. (Photo by Rick Bowmer/AP Photo)

“Rivers Forgotten” is a journey through the passages and portals of the underground waterways that lie unseen below cities. Self-taught photographer Jeremy Kai brings these forgotten landscapes to light. Photo: Beneath the Toronto area, 2011. (Photo by Jeremy Kai)

Soldiers use electronic sensors to search for missing firefighters under a line of fire trucks caught in massive gas explosions in Kaohsiung, Taiwan, Friday, August 1, 2014. A series of underground explosions about midnight Thursday and early Friday ripped through Taiwan's second-largest city, killing scores of people, Taiwan's National Fire Agency said Friday. (Photo by Wally Santana/AP Photo)

Passengers wear no trousers as they ride the London Underground in London, Britain, 07 January 2018. The No Pants Subway Ride is an global annual event where people take the public transport while they are not wearing trousers to surprise other passengers. This event takes place on the first Sunday of every year in the world's major cities. (Photo by Tolga Akmen/EPA/EFE/Rex Features/Shutterstock)

A miner sits front of the statue of St. Barbara, saint of the miners, during last working day at Hungary's last hard coal deep-cast mine at Markushegy December 23, 2014.The underground mine, west of the capital city Budapest, has to stop producing coal at the end of this year in line with a European Union effort to shut down uncompetitive hard coal mines. (Photo by Laszlo Balogh/Reuters)

People react as they ride an escalator on the London Underground during the “No Trousers Tube Ride” in London, Britain on January 7, 2024. (Photo by Hollie Adams/Reuters)