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Grande Trail Serra d’Arga 100 km trail running route — Portugal · Northern Portugal

Portugal · Northern Portugal

Grande Trail Serra d'Arga 100km: Portugal's Night-Start Granite Test, Measured

Distance

100 km

Date

Droit d’inscription

100 EUR

€ / km

€1.00

Portugal’s northern mountains: granite ridges, village charm, and a punchy 100K with real vert.

Grande Trail Serra d'Arga (GTSA) 100 km is a trail race held on October 2–4, 2026 in Northern Portugal's Serra d'Arga mountains, Viana do Castelo district. The 100 km distance starts at approximately 22:00 on October 2 — a night start that places runners in darkness for their first 6–10 hours. The course covers 100 km with 4,151 m of gain (41.5 m/km) across granite ridges, technical singletrack, and preserved rural villages. Three of the five major climbs hit maximum gradients above 50%, and nearly 10 km of the course sits above 15% gradient — genuine hiking and scrambling terrain. The defining descent — 699 m over 10.32 km starting at km 75 — is one of the longer sustained drops in the DTR database. October in Northern Portugal averages 15 rainy days; wet granite amplifies the technical demands on a course where descents average −10.70%. Entry costs €1.00/km — €100 for a UTMB Index 100K qualifier. Porto (OPO) and Vigo (VGO) airports are both approximately 61 minutes by road. Organized by Carlos Sá since at least 2014, GTSA 100 km drew 130 finishers in 2024 — up 44% on 2023 — with a cap of approximately 200 runners. It suits experienced mountain ultra runners comfortable with night starts, technical granite terrain, and a course that saves its hardest 10 km for last.

Élévation et Terrain

Mètres totaux

4,151m

D+/KM

41.5m/km

Pour référence, le Tor des Géants 330 km a 73 D+/km.

Pente montante moyenne

10.9%

Pente descendante moyenne

-10.7%

Distribution du gradient de montée

Grande Trail Serra d’Arga 100 km — uphill gradient distribution (GPX-derived, analysed 2026-05-01)
2–5%
11.1 km
5–10%
10.4 km
10–15%
7.5 km
15–20%
5.3 km
20%+
4.7 km

Profil de parcours

Analysed

Détail du terrain

Grande Trail Serra d’Arga 100 km — terrain breakdown (GPX-derived, analysed 2026-05-01)
39.6%Montée
22.6%Plat
37.8%Descente

Terrain

Pre-Alpine

Ascensions

Grande Trail Serra d’Arga climbs and descents profile

Principales montées

Grande Trail Serra d’Arga 100 km — top climbs (GPX-derived, analysed 2026-05-01)
1

4 km · 427 m gain

starts km 48 · avg 10.8% · max 51.4%

2

3.8 km · 424 m gain

starts km 92 · avg 11.2% · max 51.7%

3

8.3 km · 402 m gain

starts km 25 · avg 4.8% · max 37.5%

Principales descentes

Grande Trail Serra d’Arga 100 km — top descents (GPX-derived, analysed 2026-05-01)
1

10.3 km · 699 m drop

starts km 75 · avg -6.8% · max -36.2%

2

5.3 km · 444 m drop

starts km 52 · avg -8.3% · max -30.8%

3

4.1 km · 415 m drop

starts km 95 · avg -10% · max -47.4%

Grande Trail Serra d'Arga 100km: Portugal's Night-Start Granite Test, Measured

Why the GTSA 100km Is Harder Than 4,151m Suggests

Q: How hard is the Grande Trail Serra d'Arga 100km? A: Seriously demanding throughout. At 41.5m/km elevation density, 10.86% average uphill gradient, and just 22.6% flat terrain, the GTSA 100km delivers sustained gradient pressure with minimal recovery.

Three climbs breach 50% maximum gradient, the final 8km features the race's hardest wall followed immediately by its steepest descent, and the night start means the opening 6–10 hours run in darkness.

Course Profile — Three 50%+ Walls, 10km of Descent at km 75, and the Race's Hardest Section Saved for Last

Q: Is Grande Trail Serra d'Arga 100km a UTMB qualifier? A: Yes. The GTSA 100km is a UTMB Index 100K category race and ITRA certified.

€1.00/km for a UTMB Index 100K Qualifier in a Portuguese Mountain Village

Q: How much does it cost to enter Grande Trail Serra d'Arga 100km? A: €100 standard entry — €1.00 per kilometre — for a UTMB Index 100K qualifier. Entry rises to €105 from September 12, 2026. One of the most affordable 100K qualifier entries in Europe.

Night Start in October: What Running GTSA 100km Demands Before Dawn

Q: When does the 2026 Grande Trail Serra d'Arga 100km take place? A: October 2–4, 2026. The 100km starts on the evening of October 2 at approximately 22:00. Bib collection runs 17:00–22:00 at Praça do Conselheiro Silva Torres, Caminha.

Fichiers de course

Logistique

Aéroport le plus proche

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

Dernière vérification : February 19, 2026Site officiel →

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