This monastery was founded in 1044 by the king of Navarra above the cave where he is said to have discovered a statue of the Virgin Mary, to which he was attracted by a vulture and a partridge. The elegant Plateresque tracery and the Renaissance tombs on the lower floor of the Flamboyant Gothic-style Caballeros cloister (1518) are worthy of particular note. In the church, admire the royal pantheon (16C), the tomb of Blanche of Navarre (12C), and the 15C stalls in the coro alto.