The Serra de l'Obac, eclipsed by its neighboring mountain of Montserrat, is another great unknown. From Grimpant we bet on directing activities to uncrowded places and this is one of our favorites. In general we will walk along narrow and winding paths, with some unevenness. We highlight the tranquility of the environment, the bird's eye view of Montseny and part of the Serra de l'Obac itself. Also the visit to the cave of Simanya (not obligatory); where we will go into some depth, to reach some of the galleries. The entrance to the cave requires crouching and not having manias when it comes to getting a little muddy. The guide will give us small details; of geology, animal footprints, medicinal plants and interpretation of clouds, in an easy and simple format that will give added value to the activity.