Nimmedus Aseddiagus is a god of the Astures known from a Roman-period altar discovered on 23 July 1919 during works in the railway-station street of Ujo, in the Caudal valley of central Asturias. The dedicant, Gaius Sulpicius Africanus, bears fully Roman names, showing an outsider honouring the indigenous divinity of the place. The first element of the theonym corresponds to the Celtic word nemeton, the sacred grove or open-air sanctuary, so that the god personifies the woodland holy place itself; the epithet Aseddiagus has been explained from the Indo-European root for 'sitting', giving readings such as 'the seated one of the sacred grove'. The inscription is a key witness to the survival of grove sanctuaries among the peoples of northern Hispania under Rome.