Erlengarria IV

The entrance of the cavity is narrow and uncomfortable, leading directly to a vertical shaft of 10 metres. Afterwards, descending a small ramp of wedged blocks with allogenic deposits, one reaches a vertical step of 2 metres with access to a short gallery whose floor is very abundant in clasts. Once a scant 4 metres have been covered, the gallery widens into a small chamber, in which five possible continuations are observed. The first, on the left, is an ascending and dangerous gallery, which closes in a vertical squeeze. On the right side of the chamber there are two new possibilities of continuation, the nearest being a very narrow vertical fissure and therefore not investigated. A little further away, there is a small vertical climb that leads to a narrow and sharp fissure 3 metres long, which gives onto a small chamber dominated by clastic morphology. These blocks, in some cases of metric size, form a false floor, showing a lower zone, which evidences the continuation of the gallery. This has not been investigated due to the instability presented by some blocks.

After returning to the main gallery, two new continuations are observed. The first is a vertical shaft 20 metres deep, with a small ledge 5 metres from the start of its descent. Its section presents the clastic morphology of a phreatic tube, with a small channel at its base due to the radical cutting of the water sink (paragenetic gallery). The second option presents a vertical shaft of 3.2 metres, located at the southern end of the chamber. This, by means of a small sloping gallery, leads to the ledge of the 20-metre shaft. Once at its bottom, a fissure opens that crosses perpendicularly, closing on its left side, while three new continuations are seen. On the left, a plugging of clasts with sharp edges clean of clay that close the continuation. In the setting, after a precarious climb, there is a vertical fissure 7 metres long with numerous shafts of little depth. If the first of these is descended one can communicate with the third continuation, situated further to the right. This third entrance is full of small limestone clasts, very clean and with extremely sharp edges.

The ascending and dangerous gallery situated on the left of the small chamber has abundant lithogenic formations, notably stalactites and flowstone on walls, floors and ceilings.

The vertical shaft 20 metres deep presents at its base a small channel due to the radical cutting of the water sink (paragenetic gallery).

The entrance leads directly to a vertical shaft of 10 metres; after descending a small ramp of wedged blocks with allogenic deposits one reaches a vertical step of 2 metres that gives access to a short gallery. After a scant 4 metres, the gallery widens into a small chamber with five possible continuations. On the right side of the chamber, the nearest continuation is a very narrow vertical fissure, not investigated; a little further away, a small vertical climb leads to a narrow and sharp fissure 3 metres long that gives onto a small chamber dominated by clastic morphology, whose continuation has not been investigated due to the instability of some blocks. Back in the main gallery, the first of the two new continuations is a vertical shaft 20 metres deep with a small ledge 5 metres from the start of its descent; the second is a vertical shaft of 3.2 metres situated at the southern end of the chamber, which by means of a small sloping gallery leads to the ledge of the 20-metre shaft. At the bottom of this shaft a fissure opens that crosses perpendicularly and closes on its left side, with three new continuations: on the left, a plugging of clasts; after a precarious climb, a vertical fissure 7 metres long with numerous shafts of little depth, and, if the first of these is descended, one can communicate with the third continuation, situated further to the right.