The imposing castle dominates the image of Blankenheim. Finds indicate that a Roman fort previously stood here. Gerhard I built the castle in 1115 above the source of the Ahr. Today the castle complex serves as a youth hostel and can be visited on request. Blankenheim Castle is located directly on the hiking trails Burgen-Route and Eifelsteig stage 6.
The Gallo-Roman cemetery near the road (between Wasserbillig and Lellig) was discovered in 1970. The finds of the Gallo-Roman grave can be dated to between 75 and 100 AD, and suggest that those buried here belonged to a rich family.