System of joints born of significant tectonic activity. It has three entrances: A-5a, A-5b and A-5c. At one end it has a window that opens onto the side of the track that climbs to Pla de Tro and on the other side one that opens onto the cliff. This sector of the fissures is very clastic and many unstable blocks are found, with the possibility of continuation between them.

Via A-5a a 15-metre pitch is descended and, by ramps and boulder zones, it reaches a depth of 62 metres. After passing a boulder that blocks the way, the fissure continues, turning around and linking up with A-5c.

The entrance called A-5b leads to a series of small pitches and ramps that follow the same joint; this zone is eminently subterranean and reaches the level – 47; by means of a crawlway it connects with A-5c.

The A-5c entrance is located beside A-5b and the first 15 metres can be descended by a ramp hidden by vegetation, followed by a drop of little more than 2 metres and a ramp, arriving at a 27.8-metre pitch which, in its first 8 metres, has a ledge formed by wedged blocks from where the connecting crawlway to A-5b can be accessed. Continuing down the pitch, the level – 55 is reached with no possibilities of continuation.

The A-5c fissure, by its subaerial part, communicates, turning around, with A-5a.