Km Vertical Fuente Dé is a June uphill mountain race in Cantabria, located on the Cantabrian side of the Picos de Europa National Park. The primary race covers just 2.6 km but ascends 972 meters to a summit of 1,922 meters, resulting in an average gradient exceeding 37%. This vertical kilometer race operates under Spanish mountain-running federation rules, limits participation to 350 runners, and typically begins at 11:00 AM.
The course begins on grass and low shrubs, transitioning to a dirt trail and rocky track in its latter half, concluding above the upper terminal of the Fuente Dé cable car. The race's gradient was increased after its initial years, and it is now part of the Vertical Kilometer World Circuit. Oriol Cardona set the men's record at 33:33, and Maite Maiora holds the women's record at 39:36. The event also features youth competitions, with children competing over 1,000 meters and 361 meters of elevation gain, and cadets racing 1,500 meters with 510 meters of climb.