3451: shaft
Riaño 30T 451354 4801321 (Datum: ETRS89. Accuracy code: G) Altitude 188m
Length 144m Depth 22m
Area position

Updated 16th October, 1st December 2011

A draughting dig in the base of a large shakehole which was blocked with mud, boulders and red roof tiles. A small gulley behind the depression has a possible hole under a tree and a tiny spring higher up.

In 2011 the site was excavated to reveal an 11m shaft with a 3m climb to a sandy-floored soakaway. About 8m down the shaft an eyehole was pushed into an aven some 6m high. A tight squeeze enters a small chamber with the draught coming through a boulder choke. In the autumn, 2011 the site was re-explored looking for the lost draught. This was followed to a small chamber with no obvious way on.

In the summer, 2012, the draught was relocated coming through boulders at the bottom of the pitch. A dig, angled at 45 degrees, drops into a rift which meanders around to the top of a 5m tight pitch. This drops into various squeezes and avens but the draught is lost. It is found again at the top of the pitch and into a side passage. An aven has an excavated small tube of calcited boulders which draughts strongly. A chamber beyond drops into a stream passage. A strong draught and a good echo encourages digging.

The hole is described as "a hard, tight trip".

Reference: anon., 2010c (summer logbook); anon., 2011d (summer logbook); anon., 2011e (autumn logbook); Corrin Juan, 2013a
Entrance picture: 2010 : exploration 2011
Underground pictures : 2012
Video : draughting hole (YouTube)
Detailed Survey : pdf
Line Survey :
On area survey :
Survex file : yes (Amended magnetic declination December 2013 to align with Eur79 grid and coordinates altered to fit ETRS89 datum, April 2014.)