Situated in the Sierra de Aralar Mountains, 750 metres above sea level, in a wooded area with a high ecological value, it was first used in the Early Iron Age as a mountain stable. In the summer of 2005 it was fitted out with floating walkways and a dynamic lighting system for visitors. The cave slopes downwards and has a large natural mouth and six large rooms with abundant mineral formations. During the guided tour, which is 540 metres long and lasts an hour, three rooms are visited and it goes 40 metres underground. Caving/tourism visits are also possible, with a tour round the parts of the cave that have not been fitted out.