This route takes the road that ascends from the town of Aragües through its namesake valley and along the Osía riverbed. The first kilometres are only slightly uphill and fairly level. However, the ride becomes gradually harder as the slope steepens until finally reaching slopes of up to 10% during the last three kilometres. Here we will come to several winding horseshoe curves. The panoramic views of the valley and the mountainous environment become more and more impressive as we continue the route. We finally get to a ledge located between pastures beside the refuge of Lizara (1,505 m) at the foot of the Bisaurín.