The Agate Casket of Oviedo (Spanish: Caja de las Ágatas, sometimes in English Agate Box, "Box of Agates") is an elaborately decorated box, casket or small chest given by King Fruela II of Asturias and his wife Nunila to the Cathedral of San Salvador, Oviedo, Spain. This masterpiece of 10th century Asturian gold work is kept in the Cámara Santa (Holy Chamber) treasury.