Forat de les Gralles

The entrance of the pit is oriented to the N20O, it is 13 metres long by 4.50 wide. From the N side, one descends vertically 23 metres. The base of the shaft is occupied by small-sized blocks, plant detritus and a large quantity of guano that in some points reaches 2 metres in thickness. Towards the S side of the floor, we find enormous blocks as evidence of a clastic process. Below there is a small chamber, at the end of which opens a vertical crawl, followed by a small shaft that joins laterally to the second shaft of the cavity.

If one penetrates through the shaft located at the N end of the base of the first shaft, one descends 18 metres until reaching a ramp of clastic materials situated at -46 metres. At its bottom we find a chamber 17 metres high. At its end there is a small passage between the clastic materials that allows one to descend to -54 metres.

In the chamber 17 metres high a lithogenic process is observed.

If one penetrates through the shaft located at the N end of the base of the first shaft, one descends 18 metres until reaching a ramp of clastic materials situated at -46 metres. At its end there is a small passage between the clastic materials that allows one to descend to -54 metres.