Grande Trail Serra d'Arga 50km: Northern Portugal's Granite Qualifier, Measured

Grande Trail Serra d'Arga (GTSA) 50 km is a trail race held on October 3, 2026 — Day 2 of the three-day GTSA festival — in Northern Portugal's Serra d'Arga mountains. The course covers 50 km with 2,531 m of gain (50.6 m/km) across granite ridges, technical singletrack, and village trails starting in Dem, where the coinciding Dem Folklore Festival creates a community atmosphere rare in European mountain races.

There is no warmup. The opening climb begins at km 0.03 — 432m over 3.4 km at 12.9% average, with a 55.1% maximum pitch requiring hands on rock. The race's biggest climb (442m, km 28.23) is immediately followed by the defining descent: 693m over 8.5 km. At just 13.3% flat, recovery terrain is almost non-existent. Entry costs €1.00/km — among the most affordable UTMB 50K qualifiers in Europe. Porto (OPO) and Vigo (VGO) airports are both 61 minutes by road. October in Northern Portugal means mild temperatures but a high probability of rain — wet granite on the -52.3% maximum descent sections is a meaningful hazard.

Founded in 2014 and organized by Carlos Sá — one of Portugal's most respected ultra-runners — the GTSA 50km drew 199 finishers in 2024. It suits technically strong trail runners who want a demanding granite mountain race at one of Europe's most generous entry prices.