 Ruthweiler lies in the Pfeffelbach valley, also called the Aalbach valley, which here is quite narrow.The village sits on the valley floor at an elevation of roughly 270 m above sea level, and looming above it is the great complex of Castle Lichtenberg, which stretches up to the municipal limit, but actually stands within neighbouring Thallichtenberg’s limits.Breaking through the mountain plateau in a narrow gorge with steep rocky sides is the Pfeffelbach.