Hedemora (Sweden) - "World's Deepest Marathon". On October 25th 2025, 60 intrepid runners will take on an extraordinary challenge: to run the deepest marathon ever run. Covering 42.2km within the Garpenberg Zinc Mine in Sweden, they will descend to a staggering depth of 1,120 metres below sea level. No one has attempted a marathon at this depth before. Participants will endure temperatures of up to 30°C, in total silence and will be running in complete darkness with only their head torches for light. This pioneering event is being hosted by Boliden, owners of Garpenberg Mine. As one of the world’s safest mining companies, Boliden has ensured that safety remains paramount. Runners will be equipped with personal protective equipment and have 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 International Council for Mining and Metals, this historic endeavour captures the spirit of exploration and human resilience, and proves that limits can always be redefined. From the depths of the earth, these trailblazers will push beyond physical and mental boundaries to make history in one of the most extreme environments imaginable. www.worldsdeepestmarathon.com