An impressive limestone arch through which the río Aguanaz flows. The upstream end also has the bottom entrance to site 4171, Cueva de la Fuente del Francés. The grid reference is for the downstream, northern entrance. Just north of here a dam maintains deep water under the arch.

Reference: anon., 2015d (autumn logbook)
Entrance pictures : yes
Underground pictures :
Video :
Detailed survey : survey with Cueva de la Fuente del Francés
Line Survey :
On area survey :
Survex file : yes : with Cueva de la Fuente del Francés (4171)