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 Afelskreuz (Ablasskreuz) stands on an old Roman military road. For centuries pilgrims have been pilgrimage from Bonn-Cologne to the grave of the Apostle Matthias in Trier.
The historic quarry "Ahl" lies south of the municipality of St. Johann in the Vordereifel. The imposing rock face rises steeply north of the Nettetal and is visible from afar due to its yellowish colour.