Race the Route: Running Trail 100 Andorra's 105K Pyrenean Circuit

Andorra is the smallest country in the world with a proper mountain ultra. It is also among the most densely vertical — 468 square kilometres of Pyrenean terrain where the average altitude exceeds 1,700 metres and the highest peaks break 2,900. Trail 100 Andorra by UTMB was built to match the ambition of the country's geography, and the Ultra 105K is the race that does so most completely.

This guide is for runners planning to race or recreationally complete the Ultra 105K course, or to use Andorra as a mountain running training base.

Understanding the Course

The Ultra 105K is not a loop in the conventional sense. It is a traversal of the country — a route that visits each of Andorra's seven parishes, crossing from the Ordino valley in the north through the central massif and into the western and southern parishes before returning. It cannot be understood without understanding the geography it moves through.

Ordino to the Tristaina Lakes (Opening 20km, approx. 1,700m gain). The race departs Ordino at 1,304 metres and climbs immediately. The route heads northwest into the Tristaina valley, ascending through forest trails and mountain pasture to the glacial lakes — Estany del Mig, Estany Major, Estany de Baix — that sit in a high cirque above 2,300 metres. This section is run in darkness by the elite field and in early morning light by the mid-pack. The visual reward on a clear morning is extraordinary; the tactical reward is less: the hardest terrain is still 80 kilometres away.

The descent from Tristaina drops into the western border zone before the route begins its major climb toward the Comapedrosa massif.

The Pico del Comapedrosa Approach (km 20–45, approx. 2,300m gain). The course's defining section. The Pico del Comapedrosa stands at 2,942 metres — the roof of Andorra — and the Ultra 105K route ascends through the national park of the same name. The climb gains over 1,000 metres in the final approach to the summit area, on trails that transition from wide mountain paths to narrow, rocky ridgeline as the altitude increases.

Key details: the high sections of this climb are exposed to wind and afternoon thunderstorms. The mandatory gear (waterproof jacket rated to 5,000mm HH minimum, emergency bivy, headlamp) is not a bureaucratic formality — runners who arrive at the Comapedrosa in deteriorating weather without adequate kit are a race management problem. Prepare correctly.

The descent from the Comapedrosa section drops through the Coma Pedrosa national park into the Arinsal valley, with the village of Arinsal as an aid station midpoint. By this stage — approximately kilometre 45 — the race is settled into its hierarchy. The front runners are gone. The mid-pack is calculating whether the body they have now will survive another 60 kilometres. The back of the field is precisely where they intended to be, moving steadily.

Arinsal to La Massana (km 45–60, 1,400m gain). The western section of the course crosses the parish boundary between Arinsal and La Massana through a series of valley-to-ridge transitions that, individually, would be impressive. Collectively, at kilometre 55, they are humbling. The terrain here is technically moderate — wide trails, good footing — but the accumulated fatigue of the opening 55 kilometres transforms moderate gradient into a serious effort.

La Massana sits at the bottom of a steep valley at approximately 1,230 metres. The aid station there is the psychological midpoint of the race. Runners who are managing well will arrive, refuel, and leave with forward intent. Runners who are not managing well will make decisions — about drop bags, about pacer arrangements, about whether continuing is the right choice.

La Massana to Escaldes-Engordany (km 60–80, 1,200m gain). The course crosses into the central parishes. The route climbs through Escaldes-Engordany — one of Andorra's commercial centres — on trails that navigate around the urban infrastructure before heading back into the mountains on the eastern ridge. This section passes the Naturlandia park area and provides, on clear days, long views over the capital, Andorra la Vella.

Canillo and the Return to Ordino (km 80–105, 1,200m gain). The final 25 kilometres trace the eastern parishes — Canillo, Encamp — before the route turns north and climbs back toward Ordino through the high valley that connects the eastern and northern parishes. By this point, the night section for slower runners is either behind them or ahead of them depending on pace. The final descent into Ordino — steep, then easing, then the village streets — is the finish.

Training Preparation

The Ultra 105K requires a specific preparation. These are not transferable from road marathon training without a significant 12-16 week mountain block.

Elevation gain is the primary metric. Runners who complete this race comfortably have typically trained at 2,000-3,000m of gain per week through their peak period. Kilometre totals are secondary to vertical.

Time on feet matters more than pace. The 34-hour limit accommodates walkers who are good at walking — but this requires practice. Long training days (10-14 hours) at race pace (predominantly power-hiking on climbs, controlled running on descents) are more specific than fast 30km runs.

Altitude training is an advantage. If possible, complete at least one training week above 2,000 metres before race day. The Andorran course spends significant time above 2,500 metres. Runners who have acclimatised will have a measurably different experience in the Comapedrosa section than those who have not.

Night running practice. If you are not a sub-14-hour runner, you will run through at least one full night. Train in darkness. Know your headlamp intimately. Practice eating and navigating by headlamp.

Andorra has no commercial airport. The three closest airports each require a transfer:

• Barcelona El Prat (BCN): ~200km, approximately 3 hours by road. The most internationally connected option, with flights from most European and North American hubs. Rental cars at the terminal — the N-145 from Barcelona through the Seu d'Urgell is a well-maintained road. Alternatively, direct buses run from Barcelona's Estació del Nord to Andorra la Vella (3-3.5 hours, book at andorrabybus.com).
• Toulouse-Blagnac (TLS): ~190km, approximately 2 hours via the N20 through Ax-les-Thermes and the Pas de la Casa border crossing. Toulouse has good connections to the UK, France, and hub connections beyond.
• Perpignan (PGF): ~160km, smallest of the three airports, fewer direct connections, but the road via the Col de Puymorens is straightforward.

The border crossings into Andorra require no visa for EU, UK, and most Western passport holders. Large food and tobacco import limits exist (Andorra is not in the EU customs union) but are not relevant for race logistics.

Where to Stay in Ordino

Ordino is the race village and the natural base. The village population roughly triples during race week.

• Hotel Coma — Ordino centre, from €80/night. Basic mountain hotel with good storage for gear, close to the start/finish arch.
• Hotel Ordino — central, from €90/night. Small terrace, breakfast included.
• Rural accommodation in the Ordino valley — several small guesthouses (cases de pages) operate in the surrounding hamlets. Book 4-6 months in advance for race weekend.

Andorra la Vella (20 minutes by road) has more accommodation options including international chains. For runners with support crews who need flexibility, basing in the capital and driving to Ordino for the start works well.

Gear for Race Day

The mandatory gear list for the Ultra 105K exists for safety reasons and is enforced. Key items beyond the standard:

• Waterproof jacket: minimum 5,000mm HH, seam-sealed. June Pyrenean thunderstorms are fast and severe.
• Emergency bivy: 200g minimum. In the Comapedrosa section, evacuation in bad weather is not guaranteed to be fast.
• Poles: not mandatory but essentially universal in the field. The 6,900m of descent requires quad protection that most runners cannot provide through muscle alone. Carbon poles, 90-100cm for a 175cm runner.
• Headlamp: minimum 200 lumens, spare batteries. If you are not sub-14 hours, you run at least one night section.
• Drop bags: available at designated aid stations. Pack aid station-specific drop bags clearly labelled with your race number and the specific station name.

Food, Aid Stations, and Drop Bags

The Ultra 105K has aid stations approximately every 15-20km in the first half and more frequently in the latter sections. Hot food (soups, rice dishes, pasta) is available at the major stations from the overnight period onward.

Andorran food culture rewards the mountain athlete. The country's position between Spain and France produces a cuisine that runs on hearty mountain dishes: escudella (meat and vegetable stew), trinxat (potato and cabbage cake), game meats in autumn, and the kind of bread that is baked daily and tastes like it. The restaurants in Ordino's centre serve this food properly, without the tourist-facing dilution that affects larger ski resort towns.

FAQ

How hard is the Trail 100 Andorra Ultra 105K compared to other UTMB events? Harder than most non-Chamonix UTMB World Series events by elevation-to-distance ratio. The 6,900m in 105km (65.7m gain per kilometre) is comparable to the main UTMB race and significantly more demanding than most 100K races with less vertical. The combination of sustained high altitude, exposed ridgeline navigation, and course length makes it genuinely difficult for experienced ultra runners.

Is the course well-marked? Yes. Andorra's trail network is among the best marked in the Pyrenees, and the race adds temporary marking to the existing infrastructure. The UTMB Tracktherace app provides live tracking and is the recommended navigation backup in addition to a downloaded offline map.

What UTMB Index points does the Ultra 105K carry? The Ultra 105K is a qualifying race for the UTMB World Series. Points are awarded on a graduated scale based on finishing position and gender category. Check the current UTMB Index on utmb.world for the exact values for the 2026 edition.

Can I access Andorra without a car? With effort. Buses run from Barcelona and Toulouse directly to Andorra la Vella. From the capital, local bus services reach Ordino. For race week logistics — drop bags, support crew, gear management — a car is significantly more practical. Car rental at Barcelona or Toulouse and the drive to Andorra takes under three hours.

Where do I find other runners doing Trail 100 Andorra? Connect with athletes training in the Andorran Pyrenees and race-week groups via Find Athletes in Andorra on ZealZag.

For today's race preview and course breakdown, see our Trail 100 Andorra field report. For a different mountain challenge opening this week, see our Tour Auvergne-Rhône-Alpes Stage 3 TTT coverage.