This cave, now with a chapel installed, is where the Virgin supposedly appeared to Pelayo's warriors before their 722 CE victory over the Muslims. Weekends and summers see long queues of the faithful and curious lining up to enter. Of the cave's two tombs, one is claimed to contain the remains of Pelayo himself and his wife Gaudiosa and his sister; the other, Pelayo's daughter Ermesinda and her husband Alfonso I.
The Fuente de los Siete Caños spring, beside the waterfall and pool below the cave, promises marriage within one year to women who drink from it.