Portugal · Northern Portugal
Distance
50 km
Date
Entry fee
€50
€ / km
€1.00
New date pending
This race has already occurred. A new date for next year’s edition is pending.
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.
Total Meters
2,531m
D+/KM
50.6m/km
For context, the Tor des Géants 330 loop has 73 D+/km.
Avg Uphill Gradient
11.9%
Avg Downhill Gradient
-12.2%
| 2–5% | 4.2 km | |
|---|---|---|
| 5–10% | 6.5 km | |
| 10–15% | 4.9 km | |
| 15–20% | 3.3 km | |
| 20%+ | 3.0 km |
| 43.9% | Uphill |
|---|---|
| 13.3% | Flat |
| 42.8% | Downhill |
| 1 | 3.2 km · 442 m gain starts km 43 · avg 13.8% · max 31.3% |
|---|---|
| 2 | 3.4 km · 432 m gain starts km 0 · avg 12.9% · max 55.1% |
| 3 | 5.5 km · 364 m gain starts km 9 · avg 6.6% · max 31.1% |
| 1 | 8.5 km · 693 m drop starts km 28 · avg -8.2% · max -33.1% |
|---|---|
| 2 | 5.3 km · 447 m drop starts km 3 · avg -8.5% · max -27.4% |
| 3 | 4.1 km · 417 m drop starts km 46 · avg -10.0% · max -52.3% |
Seriously demanding for its distance. At 50.6m/km elevation density, 11.89% average uphill gradient, and just 13.3% flat terrain, the GTSA 50km sits close to UTMB in gradient intensity for half the distance. The race opens with a 432m climb from km 0.03 and features near-constant ascending or descending. Wet granite in October adds technical risk throughout.
Yes. The 50km is a UTMB 50K Series qualifier and ITRA certified.
€50 standard entry — €1.00 per kilometre — one of the most affordable UTMB 50K qualifiers in Europe. Entry rises to €55 from September 12, 2026.
October 3, 2026 — Day 2 of the three-day GTSA trail festival.
Porto (OPO) and Vigo (VGO) in Spain are both approximately 61 minutes by road to the race area. Porto has better international connections; Vigo is useful when travelling from Spain. Good rail connections exist from Porto to Viana do Castelo and Caminha, with a short taxi transfer for the last mile.
Nearest airport
Porto (OPO) / Vigo (VGO)
Notes
Start: ~1–1.5 hrs (OPO) or ~1 hr (VGO) by car to Caminha / Public transport: good (train Porto→Viana do Castelo/Caminha) + taxi/bus last-mile / Accommodation: good supply in Caminha/Vila Praia de Âncora/Viana do Castelo; book early
Ibiza Trail Maratón 48 km
Exclusive Discount - use ITMF-DISCOVERTRAIL26 CODE for 50% at checkout
