Del Roble

The mouth of the pit measures 7x4 metres and the total depth is 82 metres. The first 10 metres begin with an inclination of 50 to 70º, followed by an absolute vertical. The «Gran Galería» is 65 metres long and approximately 5 metres wide and 5 metres high. The total length is 483 metres.

At the foot of the pit, the passage towards the Norte leads, after 40 m of travel, to the bed of an underground river. In the gallery towards the Southeast, after 100 m of travel, there is a shallow pool of water. The pit ends definitively in a shaft where the water visibly continues its course by filtration through a bed of rounded pebbles and sand. The galleries sump from the end of the 100 m shaft, so caution is needed in the rainy season; the old locals say that in times of heavy rain the water even came out of the mouth of the pit.

At the foot of the pit there are two passages: 1-Towards the Norte, a low roof that leads, after 40 m of travel, to the bed of an underground river. 2-Towards the Southeast, the joint of the pit continues along a gallery that is at first very high, then gradually lowers. After 100 m of travel one comes upon a shallow pool of water, where two successive low roofs begin, separated by a higher stretch, until reaching a crossing of galleries. To the right, a first passage leads, after climbing 4 metres, into a shaft; from this shaft two secondary galleries radiate that return to the main passage. At the same crossing, to the left, the main passage continues first with a low vault, then in a joint 10 m high, where it is necessary to descend 5 metres down a ladder formed by enormous blocks of debris. They end in a low roof cut inclined upwards and full of rounded pebbles, which leads into the «Gran Galería». Then begins the Gran Diaclasa: it descends first 10 metres by ladder and then another 10 m in a vertical drop. After 50 metres an almost horizontal gallery begins, very wide. It ends definitively in a shaft.