Starting from Beget, we will head to the Roca, a farmhouse located to the east of the village; it can be reached by car along a track. About 30 m before reaching the house, a discreet path branches off to the right, passes behind the farmhouse and begins to climb the torrent dels Trulls along the left hydrographic slope. We will follow it for a good while. We will cross the torrent that comes down from the pla de Falguers at a very shady spot. From here, we will continue for about 12 more minutes to a point where the path comes very close to the bed of the torrent dels Trulls, shortly before the path overcomes a small cliff. From here, we will descend to the torrent and, shortly after, we will find the formation of la Tosca, in which the cave has been excavated.

It can also be accessed (and the itinerary is shorter) from the pista del Comanegra. The small path, descending, starts a little beyond Can França, a ruined farmhouse located on the same track.