THOUSANDS of thrill-seekers across the world flocked to their local tube stations donning their pants in honour of No Trousers on The Tube Day.
The bizarre annual tradition which is in its ninth year, began as a small prank in New York almost sixteen years ago, and has now spread to more than 660 cities - but Londoners appear to have taken it to a whole new level.
More than 400 Londoners braved frosty conditions on Sunday afternoon when temperatures plunged to a chilly 3C.
The event's founders said the bizarre tradition was launched to simply make people laugh on their commutes.
Improv Everywhere, the self-styled New York-based prank collective, said: "The idea behind the No Pants Subway Ride is simple: Random passengers board a subway car at separate stops in the middle of winter without pants.
"The participants behave as if they do not know each other, and they all wear winter coats, hats, scarves, and gloves. The only unusual thing is their lack of pants."