Dercetius is a mountain divinity of the upper Ebro fringe of Celtiberia, in the Sierra de la Demanda of modern La Rioja. His cult is documented by a first-century AD votive altar dedicated in the dative form 'Dercetio', found near San Millán de la Cogolla, and his memory persisted long after paganism ended: in the seventh century Braulio of Zaragoza, writing the Life of Saint Aemilianus, still called the peak on which the hermit saint retreated 'Dircetius mons'. He thus belongs to the well-documented Hispano-Celtic pattern of deified mountains, in which the same name designates both the god and his peak; the theonym is usually explained from the Indo-European root meaning 'to see', fitting a god of high, far-seeing places.