We go over a stream to the next little bridge which indicates the beginning of the route. It seems easy at first, but the trail narrows and becomes a mountain path with rocks and mud. Hiking boots are a must. At times the path forks but all the detours lead back to the same route. We go up non-stop on a zig-zag trail.
The trail becomes more bearable as we reach the Pineta Look-out point. Poco a poco el itinerario se hace más llevadero y tras una larga y pedregosa senda llegamos al balcón de Pineta. The view of the north-face glaciar and valley is awesome. Continuing up the valley we find the Astazous. The environment is totally alpine and photos are highly recommended. We are in the heart of the Pyrenees.

We continue a bit up the valley, hugging the opposite ridge of Perdido and the glaciar. It takes about half-an-hour to reach the frozen Marbore lake (ibon). Frozen for most of the year, we can see its clear waters in summer. This great mountain lake is surrounded by rocks with no vegetation. A grand reward after a long hike. The route is complete, but now comes the hard part: Getting back down! Its long and steep and weak knees should not risk it.