Geoparque Unesco

GR 10 A lake among the oldest rocks in Sobrarbe

Lake Pinara and Puerto Viejo

About 65,000 years ago, glaciers covered much of the Pyrenees. Today, only a few glaciers remain as a reminder of past Ice Ages, but these mountains are full of evidence of their glacial past. Valleys, ridges, cirques, basins, waterfalls, mountain lakes... are all remnants of when great glaciers covered the region.

This geo-route takes us to Pinarra Valley, where the traces of past glaciers are clear to see, and it leads to the small and usually solitary mountain lake of the same name. If you have a little more time, you can make your way up to Puerto Viejo, on the border with France and the boundary of the Pyrenees National Park, from where you can enjoy a magnificent view of this beautiful area, which has some of the oldest rocks in Sobrarbe that originated over 480 million years ago.

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  • Route: Southern end of the Bielsa Tunnel to Lake Pinarra and Puerto Viejo. PR HU-182
  • Type of Route:Linear (return along the same route). There are three options: (1) visit the mountain lake, (2) visit Puerto Viejo, (3) combine both and visit the mountain pass first and then visit the lake on the way down.
  • Difficulty level:Low-medium for all options. The path is not difficult and the gradient is moderate (a rise of 750 m on the longest option), although the various options proposed may make the route shorter. Visiting the lake requires crossing an unmarked area that is easy and clearly identifiable; however, in foggy weather it may be difficult to find your way. Avoid climbing to Puerto Viejo if there is heavy snow, as the mountainside may be unstable and avalanches may occur
  • Duration: 1.5 hours (out) if you visit the lake. Add another hour for the return journey. 2 hours if you visit Puerto Viejo. Add another 1.5 hours for the return journey or 2 hours if you stop to visit the lake.
  • Length 4 km (one way) to the lake; 4,5 (one way) to the mountain pass; 10 km (both ways) if you combine both visits.
  • Gradient: 400 m on the way up (and the same distance on the way down) to access the lake; 710 metres up and the same distance down for the mountain pass. If you combine both visits, the difference in altitude will be 750 metres (up and the same distance down).
  • Starting point The car park on the right-hand side of the road to France, near the southern end of the Bielsa-Aragnouet tunnel on the A-138, which connects Aínsa with the French border. Next to the car park, which can hold half a dozen cars, there is a Tunnel control building.
  • Comments Trekking sticks may be useful on the grassy sections of the route. At the head of the Ordiso Valley (even above the lake), there are a lot of cattle; therefore, it is advisable to take your own water as almost all the rivers are used by the cows. This is a long route and its main attraction is Ordiso Valley, consequently all the Stops suggested are in this sector of the route.
  • IMPORTANT: It is not advisable to replenish your water except at the place indicated due to the presence of cattle

Recomentations in your visit to Sobrarbe-Pirineos Geopark

  • Safe visits, unforgettable experiences. There are companies who collaborate with the Geopark where you can hire specialized guides to make your tour a unique and safe experience.
  • Respect the geological outcrops. Do not break off samples of rock, mineral or fossils; anly take the loose pieces

Avda. Ordesa 79. 22340 Boltaña. Huesca. 974 518 025.