Located in the southern province of Castellón, the caves of San José are the underground river found in the town of Vall d’Uixo within the Natural Park of Sierra Espadán, making it the most important tourist spot in the area .

The travel time to the caves takes about 40 minutes, performing a route of about 550 meters on foot and boat and a dry by a gallery of 250 meters. There is another section of approximately 2000 meters is not open to the public.

Despite the many visits of cavers they not know the source of the river or the end of the cave.