The main entrance to the cave known as Cova Fosca is below the precipice, where one can see fault openings and a pair of faults separating a large rock mass. The cave is in the fault itself, about 3 metres above the base of the precipice. In front of the mouth, a series of stepped terraces extend to the bed of the ravine, through which a path passes. A mountainous dyke, in which several faults can be observed, borders the top of the cavity of the precipice. About 30 metres from this entrance, towards the west, bordering the precipice and on top of the ravine itself, there is another entrance or balcony at medium height. From this entrance a fault opens in a westerly direction, about seven metres long and 70 centimetres wide, which separates a pyramidal cliff from the mother rock and forms the entrance. After a metre and a half, walls initially built by the shepherds and later by Ebo’s Town Hall, leave an entrance of no more than 80 centimetres.

After entering through the entrance which faces south, a chamber opens up, measuring from 2 to 7 metres high by 5 metres wide, which starts going northwards and turns to the west in the intermediate section, with a total route of 18 metres. At its end there is another mouth 6 metres high by 2 metres wide, in the shape of a spindle. This second mouth opens 10 metres above the base of the precipice and about 20 metres from the bed of the ravine. In the middle of the room, in a north-east direction, begins a tunnel that narrows to 7 metres, with a passage leading to a tube of about 70 centimetres in average diameter with 10 metres in length. Its floor is covered by loose stone rubble. The tunnel leads to a room 2 to 3 metres high by 8 metres long and up to 4 metres wide, although, in the northern end, the ceiling descends forming an angle with the ground. Almost at the end of the chamber and adjacent to the right, there are some stalagmite columns and, on the ceiling, a decompression chimney formation that rises to about 6 metres, with its walls full of concretions mainly due to mudflows. Continuing north, the gallery narrows to form a corridor in which the ceiling rises again in another 5-metre-high decompression dome. After a further 5 metres, it widens again to narrow once more and change direction towards the northeast, leading to the main room of the complex (Sala Carmina). This room, which is oriented from southwest to northwest, is 8 metres long by 4 metres wide and up to 5 metres high. At the bottom there is a narrow hole that gives way to a rear room of 8 metres in length in an eastern direction. Above the narrow passage, a room or upper passage opens up that joins the two rooms at ceiling level, opening a 5-metre-deep chasm which is easily accessible. In this upper room there is a tunnel with an average diameter of 60 centimetres and a length of 8 metres, which extends in a westerly direction in its initial part and north-westerly in the last room, with a maximum width of 2.5 metres and from 5 to 7 metres in height. After a steep slope, at the bottom, another narrow passage opens and offers access to the last room, which is 4 metres long and 70 centimetres wide at the highest part, and which widens at the end. This room is arranged from north-northeast to south-southwest and is 20 metres from the surface. Above the roof there is a new dome forming a small room connected to the previous one at medium height.