Tresviso Caves Project

Tresviso Caves Project Gazetter

T511: Cueva del Yim Y Yong

(Jim & Johns Cave)

Area:Sierra del a Corta
East, North:360554, 4787736 (nearby)
Coordinate Quality:Google Earth
Long, Lat:-4.7172073670733, 43.229505010897 (map)
Elevation (m):1430
Length (m):0
Depth (m):-25
Active Lead:
Survey Available:


Behind derelict cabana


Gated cheese cave Entrance


At the back of the cave, a decent sized opening leads onto the top of a steep loose floored tube. Beyond the tube is a large inclined rift, (descended on a ladder) to the 10m below.
The rift extends for about 50m in each direction - at one end is a constriction and at the other the roof comes down to meet the floor. A tube observed by the top of the pitch came down into the rift, and between this and the pitch a short climb up a tube with a loose rock floor leads to a possible way on. However, it was obstructed by rocks and very unstable)

A tight draughting hole is the way on. A pitch (?M) lands in a small chamber surrounding the ledge which appears to have been formed by the flow from a two feet diameter phreatic entering the chamber at about chest height. The rift continues to another tight constriction. This leads to the third pitch (very tight). Climbing down the pitch leads to a mud floor and a small, shallow pool. To the right of the third pitch another inlet enters.

Beyond the inlet, a short crawl leads into another small chamber, with a hole in the floor filled with a muddy deposit which appeared to be the result of a section of false floors falling from above.

The hole seemed to be draughting slightly around the edges of the mud plug. A small streamway with a trickle of water in it entered the hole from the West. This leads back along a deeply downcut vadose passage into a small, pitch decorated aven. The water flows from a small heavily calcited phreatic tube high in the opposite wall. At least one of the several other tubes entering the aven is intermittently active, but one or two are obviously fossil, having become heavily calcited and muddied. A substantial false floor crossed one half of the aven at head height, and is extensively decorated with flowstone.

Digging in the mud hole may well yield a way on, as the number of decent sized inlets suggest that a good volume of water once flowed down it.


L.U.S.S. (1995) Summary report to GPF.