From kilometre 13.750 of the B-122 road from Terrassa to Rellinars, a wide track leaves to the right towards the house of la Boada. After crossing the riera de Rellinars for the first time, at the point where the font de Carlets lies on the left, one reaches a flat area on the right of the track (la Feixa del Gram). Once past this point, continue along the first fork to the right, which leads to the old house of la Calsina. After crossing the riera again, the track climbs and, after about 100 metres, at the start of a straight stretch, there is a fairly wide flat area on the left. From here one must cross the riera de la Saiola and continue for about a hundred metres with a drop of some 15 metres to find the entrance. Right beside it there is an artificial shaft, completely round, about 4 metres deep.