027 Cueva Oñite
Ozana VN54419511 Alt. 254m Length included with Risco (025)

Updated 19th February 1999; 14th May, 12th November 2002; 6th November 2003, 8th October 2005

Entrance is a pitch of 6.5m that can be free climbed. This leads into the streamway or a few high level chambers can be reached. After a short crawl, water from a sumped passage on the right is met and for the next 500m the cave is a sporting vadose streamway. At the end is an 18.6m pitch into the final chamber of Sima-Cueva del Risco.

On the left of the streamway, 30m before the pitch, a small passage leads into a large fossil gallery, Mavrino Inlet,  which soon chokes. From this passage the 2005 extensions lead off.
Gulag Gallery starts as a calcite-floored side passage on the left at the start of Mavrino Inlet. This goes for about 100m with signs of previous entry to a low point which was dug out to a small chamber and a 5m free climb to a bedding plane, ending at the top of a meander passage. This enters a crawl with boulders that continues past holes in the floor and enters walking size passage with stal and passages in the roof. The passage rises to near the surface with tree roots: Gulag Gallery has almost come full circle back to the Oñite entrance with a length of 446m.
184m of extensions on the opposite side of Mavrino Inlet provided the Sala Carballo Pitch Bypass.
The First Circle - known passage - was surveyed in 2005 and increased the length of the Risco System to 9859m.

References: anon., 1974a (survey); Kendal Caving Club and Manchester University Speleological Society, 1975; Fernández Gutiérrez J C, 1975; anon., 1975a; Manchester University Speleological Society, 1982 (survey); Mills L D J, 1981; Corrin J S and Smith P, 1981; García José León, 1997 (survey and photo); pers comm (email 13/5/02); anon., 2005b (Easter & summer logbook)
See 025 Risco
Entrance picture : yes
Underground picture(s): streamway  Mavrino Inlet  male gyas titanus
Detailed Survey : preliminary pdf of 2005 extensions with original passage
Line Survey :
On area survey : 1975 Ozana area map. Not a lot of detail. low res  high res
Survex file :