World's Deepest Marathon
🏃♂️ 42 km
🌍 INT
On October 25th 2025, 55 intrepid runners took on an extraordinary challenge: to run the deepest marathon ever run. Covering 42.2km within the Garpenberg Zinc Mine in Sweden, they descended to a staggering depth of 1,120 metres below sea level. No one had attempted a marathon at this depth before. Participants endured temperatures of 24°C and 72% humidity, in total silence and ran in complete darkness with only their head torches for light.
This pioneering event was hosted by Boliden, owners of Garpenberg Mine. As one of the world’s safest mining companies, Boliden ensured that safety remained paramount. Runners were equipped with personal protective equipment and had access to rescue chambers, adhering to stringent protocols designed to protect them in this unique subterranean environment.
Organised by learning and development specialists BecomingX, co-founded by adventurers Bear Grylls and Paul Gurney, alongside the ICMM, this historic endeavour captured the spirit of exploration and human resilience, and proved that limits can always be redefined. From the depths of the earth, these trailblazers pushed beyond physical and mental boundaries to make history in one of the most extreme environments imaginable.
This pioneering event was hosted by Boliden, owners of Garpenberg Mine. As one of the world’s safest mining companies, Boliden ensured that safety remained paramount. Runners were equipped with personal protective equipment and had access to rescue chambers, adhering to stringent protocols designed to protect them in this unique subterranean environment.
Organised by learning and development specialists BecomingX, co-founded by adventurers Bear Grylls and Paul Gurney, alongside the ICMM, this historic endeavour captured the spirit of exploration and human resilience, and proved that limits can always be redefined. From the depths of the earth, these trailblazers pushed beyond physical and mental boundaries to make history in one of the most extreme environments imaginable.