Endurance runners descended more than 3,000 feet underground to compete in one of the most unusual races in the world—the deepest marathon ever staged.
The unique event took place near Llanwrtyd Wells in United Kingdom, where athletes navigated dark tunnels and narrow passages deep beneath the surface. Participants wore headlamps and safety gear to light their way as they ran through the subterranean course.
Organizers said the extreme location required careful planning, including ventilation systems, safety teams, and clear route markings to guide runners through the underground environment.
Officials from Guinness World Records verified the marathon as the deepest marathon held underground, recognizing the event as a new record.
Despite the challenging conditions—limited lighting, cooler temperatures, and uneven terrain—dozens of runners successfully completed the demanding race.
Participants described the experience as both thrilling and surreal, noting that running through dark underground tunnels offered a completely different challenge compared with traditional marathons.
