In the 1st millennium BC, Celts settled on the Staffelberg. Around 200 BC, the simple Early Celtic fortification was expanded into an oppidum, covering an area of 49 hectares, that was protected by a 2,800-metre-long defensive wall and ditch against the inhabitants of the neighbouring Jura lands. Menosgada was the northernmost oppidum in Bavaria. In the centre of the site is an acropolis measuring 3 hectares in area.