Updated 27th June 2022

A well known cave in the Riotuerto district which was explored and surveyed by the Speleo Club Cántabro in 2009. The entrance lies uphill of the La Riega resurgence. (In the autumn 2016, the resurgence was the scene of a successful water trace from a Moncobe hole (5182) being explored by the GE Pistruellos.)
The centre line reconstruction below gives a survey length of less than 1km.

References:
Entrance pictures :
Underground pictures :
Video :
Detailed survey : SCC survey
Line Survey :
On area survey :
Survex file : Reconstructed from the SCC survey