Pou del Coll d'alzina

Entrance 1.5 metres in diameter opened in the layer of topsoil and altered conglomerate, in the middle of some holm oaks. A 4 metre drop to a small chamber of conglomerate decomposition. Continuation of the shaft in the SW end of the chamber, on an E20S joint, very clearly observable. The section of the shaft is typically oval and elongated in the direction of the joint, with a small channel due to the infiltrations from the lateral conduit. At -15 metres the shaft cuts a layer of marls 15 centimetres thick. Further down there is a small ledge that takes the shaft towards the W. The floor (-32) forms a floor plan of 9 x 3.5 metres in which an E-W joint can be seen at the N end. To the W there is a small gallery rising from the floor occupied by an accumulation of decalcified conglomerate, the base of a lateral spindle 11 metres high, up to a layer of marls that limits it above.

From here the infiltrations begin, especially abundant according to the time of year. At the -9 level, in the W end of the shaft there is a lateral conduit that brings new infiltrations.