106 Torcón de Riaño
Riaño 30T 452286 4799454 Alt. 265m  Length 120m Depth 95m

Updated 30th August 1998; 7th June 2002; 8th November 2003; 9th October 2004

The entrance is well hidden in a densely vegetated hole opposite a cabaña. A bouldery entrance slope meets a trickle of water from a pipe which then flows down the pitch. The first drop of 7m is followed immediately by the main pitch of 91.5m. At the base, a narrow vadose streamway sumps after 100m. This is about 50m from the upstream sump in 3rd River Inlet in Cueva de la Hoyuca (107), and they presumably connect.
On the left of the entrance slope is a stoop / crawl which splits: the right hand route rejoins the main way on, the left hand route needs to be pushed through a wet crawl.

A second exploration was carried out on 5th August 2004 using electric light and SRT (not small carbides and ladders) twenty nine years after the first exploration. The sketch below shows that there are possible passages on the way down to look at, but no way on over the top of the sump was found.

References: anon., 1975b (logbook); Kendal Caving Club and Manchester University Speleological Society, 1975 (survey); Corrin J et al, 1981b; Mills L D J and Waltham A C, 1981 (survey); Corrin J S and Smith P, 1981; Manchester University Speleological Society, 1982; material in file; anon., 1998d (logbook); anon., 2004d (summer logbook); Corrin, Juan 2006
Entrance picture :
Underground picture(s): entrance slope
Below: Ali Neill on the main pitch. Pictures by Torben Redder.

Video : (by Juan Corrin) Entrance rift    Walk down to pitch head   Rigging 1  2  pitch head  7m shaft top  echo at p93
Sketch : main pitch with possible passages leading off. (from anon., 2004d)
Detailed Survey :

1975	known cave	low res	high res
1980	with Third River Inlet	low res	high res

Line Survey :
On area survey :
Survex file : yes
Miscellaneous : team for the first exploration in 1975