Going along the road from Alcover to Capafonts (TV 7041), before reaching Mont-ral and a few metres before reaching Km. 10, a track leaves, asphalted at first, which crosses the Pla de les Perdius. We will always continue straight, ignoring the forks, until the track ends in a widening of it in the middle of the forest, on the ridge of the serra d'en Clarà. From this point and in a N direction a path leaves that takes us to the avenc del Cabirol, after descending a short but steep slope, almost reaching the avenc del Cabirol which is right next to us on the left, we find on the right a cairn that indicates the start of a half-lost path that runs through the interior of a kind of wide natural trench, after about 90 metres we will see on the right on a rocky wall, the cave-shaped entrance of the avenc de la Carbonera, we will follow the path leaving this rocky outcrop on the right until reaching the upper part. At this point and before starting to descend we will head to the left in a NE direction, where we will soon find the two entrances of the avenc de l'Arbre, we will continue a little further on starting the descent of the slope where we will find the entrance of the NR-11, the NR-10 is just below, descending a small step, among some large blocks.