The Palacio Ducal de los Borgia is in the top part of Castelló de Rugat, in Plaza Palau. It was built by the Bellvis family in the 14th and 15th centuries. It subsequently passed into the hands of the Borgias, who extended and improved it. The palace was used by the family as a summer residence and was enjoyed by four generations of the Borgia family. The property was finally acquired by the Frasquet family, who were local landowners and the last people to own the building.
Nowadays only part of the façade is visible, as well as traces of the defensive barbican and the vegetable garden surrounding the palace.