Salomon Ultra Pirineu is an autumn trail-running series held in Bagà, a small mountain village in the Catalan Pyrenees. It features races over VK, 21K, 42K, and 100K. The 100K race, which lends the event its name, begins and ends in Bagà. It guides runners through the rugged mountain terrain of Parc Natural del Cadí Moixeró, covering approximately 100 to 102 km with 6,600 to 6,700 metres of elevation gain.
The course includes high mountain sections, steep ascents, varied terrain, and mountain-hut areas, distinct from smooth roads or simple forest paths. Participants arrive from over 50 countries, creating a mix of local mountain experts, international ultra runners, and keen amateurs. Kilian Jornet's 100K record, set in a previous edition at just over 10 hours, reflects the high caliber of competition and the route's challenge.