Tresviso Caves Project

Tresviso Caves Project Gazetter

T190: Torca Septrin


Area:Pico Boro
East, North:360109, 4786462 (nearby)
Coordinate Quality:GPS
Long, Lat:-4.7223619491238, 43.217955625491 (map)
Elevation (m):1696
Length (m):273
Depth (m):-180
Active Lead:
Survey Available:


Follow a sheep track north west from the boggy area in the bottom of the depression below Pico Boro. After walking 300m and climbing 100m the entrance is seen. The entrance is a large surface feature 4m by 4m with a small cliff at one side.


The entrance is a large surface feature 4m by 4m with a small cliff at one side Entrance


A hand line is necessary to descend the snow slope from the surface. At the bottom, to the right is a small blind chamber.

To the left duck under a small 'doorway' into a chamber. The immediate impression is of an old dry cave, with brown stalactite and collapsed reddish boulders. Traverse over a small blind pit to the head of the first pitch, which is 12 m in a clean shaft and leads to the head of the sloping ladder climb.

At the bottom of the ladder the pot closed down with tight rift development to the left and right. To the right the rift is too tight but descends to the same shaft as the left. On the left a short vertical squeeze of 1m, in which stemples were placed to aid ascent, opens out onto a short pitch which twists down to a further pitch of 34m. Here the pot widens out a large natural spike gives a fee hang down the centre of the shaft. Again there is an abundance of brownish calcite.

The pitch lands on a sloping boulder floor. This quickly leads to a parallel shaft, and the next pitch of 25m. The hang is from the corner of the shaft, but soon the rope is hanging free in the centre of a very large shaft, with deepening blackness as the shaft widens. What appears to be a stream can be seen below but this in fact a puddle on the spacious, flat, rocky floor. Water trickles down the shaft from an unseen inlet. A small trickle runs away at the bottom of the shaft into a rift which rapidly becomes phreatic, and a pool is reached at stream level.

2010 - rift was capped and access given to section of sharp crawls leading down 2m climb to small chamber. Hole to right of chamber leads to approx 20m of climbs on sharp rock.

2014 - unable to progress through rift discovered at end of 2010. Further back is series of parallel crawls to further pitch of approx 20m. All close down

2018 - The constriction at the 2010 limit of exploration was passed to a small chamber. To the right, closes down again and the higher-level fossil passage is impassable.

At the bottom of All Go - No Show (discovered in 2014) a small phreatic tube is constricted in nature and no way to turn around, exploration was wisely abandoned.

A 'walking passage' lead at the bottom of No Room at the Inn is actually an impassable tight, 30m high rift. However, a phreatic fossil tube bypass above this leads to 20m of miserable crawling. After a calcited constriction, a small (7m) pitch, Backshot, leads to a pretty fossil mud chamber.

A small window in the foot of the chamber leads to a tight stream. Upstream closes down, and a muddy fossil chamber has no way on. Downstream is a tight squeeze with a larger, standing room streamway passage visible beyond. This likely connects to the other side of the 'walking' lead but what lies beyond is unknown


Anon. (1982). "Cave Descriptions and Surveys. Septrin". En "Tresviso '81". LUSS. Pag. 19.
Sefton, M. (1984). "Cave explorations around Tresviso, Picos de Europa, Northern Spain.". Cave Science vol. 11-4:199-237.
Cantabria Subterranea 1997, 2010
Tresviso 2010 (SBSS)
T.C.P. (2014, 2018)