Updated 6th November 2003; 8th, 12th February 2024

The cave was revisited, extended and completely resurveyed in October 1995. The original description of an uninspiring, wet cave does not fit! The cave was again re-surveyed for Survex detail in 2024.

The deep, wooded entrance shakehole has a bank of tufa, the water from this has coated earth pellets and other detritus to make "pearls". The low entrance chamber has two too-tight passages to the left. The route down to the right reaches walking passage to a 3m climb up out of the stream and a tight squeeze into a chamber with calcite columns. To the left, a stooping passage rises to a choke, with a tighter route to the right which chokes to the left but continues down, unexplored.

The main passage swings to the right passing along a short traverse and encounters some fine sediment banks, with holes down to the very tight streamway below. To the left, a false-floored passage soon chokes. A hole part way along needs descending and prevented further exploration in 2024. After a further 15m, another short passage on the left also chokes. The cave then lowers to a flat out crawl, entering larger passage on a bend.

After a further 15m, the passage divides at two 3m climbs down. The eastern climb encounters boulders and eventually chokes in all directions. The southern passage contains avens. The climb down to the north enters a nicely shaped vadose passage which rises at the end and chokes very close to the main route already traversed - this passage needs tackle at the start to re-investigate.

A large male Lithobius deroutae Demange is described by Ortiz in Algunos crustaceous y miriapodas cavernicolas de la Region de Matienzo, Santander (Ortiz E, 1968).

After the January 2024 resurvey visit, it is thought that the cave needs another trip with tackle to investigate drops and possible digs and complete the Survex detail. An interim survey is linked below.

References: Fernández Gutiérrez et al, 1966 (survey); Kendal Caving Club and Manchester University Speleological Society, 1975 (survey); Manchester University Speleological Society, 1982 (survey); Mills L D J and Waltham A C, 1981 (survey); Corrin J S and Smith P, 1981; Ortiz E, 1968; anon., 2024a (January, February logbook)
Entrance pictures : 1995, 2024
Underground pictures: 1995 and 2024
Detailed Survey : from 1965: low res  high res.  From 1995:  scale 1:1000 : original drawing for the 1995 survey : 2024 version 24.1
Line Survey : January 2024
On area survey : 1975 Ozana area map. Not a lot of detail. low res  high res
Survex file : yes (Amended magnetic declination December 2013 to align with Eur79 grid and coordinates altered to fit ETRS89 datum, April 2014.)