Updated 19th November 2007; 17th April, 1st October 2008; 5th May 2009

A very tight tube about 15m S of Torca Andando, site 689. This was enlarged in the autumn of 2007 and entry gained to a narrow passage to the head of a 5 second drop, probably over the final chamber in site 689, Torca Andando.
The account from October 2007 follows:
The cave is situated 2 metres up the bank at the side of the track 15 metres beyond (south of) Torca Andando. An excavated entrance crawl pops out into a small chamber with a sediment floor after 2 metres. A tight inlet on the left brings in a trickle of water and the main way on is a jagged rift, 1 to 2 metres high with a phreatic roof tube. A second small inlet enters on the left at floor level; this chokes in calcite after 3 metres.
Immediately beyond, a flowstone boss forces one to crawl over moon milk to a keyhole shaped passage and a narrow rift dropping away into blackness. A traverse above the rift on sediment covered ledges widens dramatically before a large wedged boulder can be reached.
Rocks dropped down the pitch have been timed at over five seconds, hitting one ledge. The pitch probably connects with Andando though the rift appears to bell out to the west and could possibly fall beyond the final chamber. Disto readings were taken though the only measurements obtainable were following the north west wall down from 11 metres to 27 metres. Below this was a black hole and the disto beam got diffused.
A strong draught blows into the cave and on reaching the pitch it is immediately sucked down and no draught can be felt on the traverse. Smoke tests were carried out at the entrance to Andando first by Lugger's pipe and then by Phil's olive branch and no hint of a draught could be detected. Tackle is still in-situ on Andando's second pitch. Surveyed length for Tres Idiotas is 20 metres and pitch head is less than 2 metres below entrance. Pitch head needs gardening of sediment and bolts installing for safety line on traverse. Traverse is an adrenaline rush when things start dropping away below you.

In November 2007, the site was further enlarged and rocks thrown down the large drop were heard at the entrance to Andando. At Easter 2008, the pitch was made more accessible; there was a good draught blowing out.

During the summer 2008, site 2786 was tackled up and surveyed to a point where it appeared to link with Andando. However, the explorer was not sure that a connection had been made as the cave was not recognisable on the survey. Over Easter 2009, the shafts were explored and surveyed as one site, 2786. The drawn-up survey and re-written description will appear in due course .

Reference: anon., 2007d (summer logbook); Corrin Juan, 2007a; anon., 2007e (autumn + Christmas logbook); anon., 2008c (Easter logbook); anon., 2008e (summer logbook); Corrin Juan, 2009
Entrance picture: yes
Underground picture : yes
Video :
Detailed Survey : with Torca Andando
Line Survey :
On area survey :
Survex file : sites 689 and 2786 (Easter 2009) (Amended magnetic declination December 2013 to align with Eur79 grid and coordinates altered to fit ETRS89 datum, April 2014.)