The romantic Rhine valley between Brohl-Lützingen and Rolandswerth is certainly worth a trip, whether by car, train, bike or boat. The fairy tale forest at Bad Breisig and the wildlife park at Rolandseck are especially suitable for children.
There are many lovely castles around the Rhine/Mosel valleys. Particularly noteworthy are Burg Eltz near the Moselle river (www.burg-eltz.de); the ruins of Burg Rheinfels and Marksburg near Koblenz - the best preserved Rhine castle.
The Brohl Valley was formed by powerful volcanic activity that left a permanent mark. A trip with the "Vulkan Express" narrow-gauge railway is highly recommended. A couple of times a month it is pulled by a steam train. See: www.vulkan-express.de. Laacher See (a volcanic lake) and 800-year-old Maria Laach Abbey are also worth a visit.
The many wine festivals from April to September bear witness to the Ahr Valley's extensive wine-making tradition. Special attractions are the Red Wine Trail (Rotwein-Wanderweg - for hiking), the Roman Villa on Silberberg hill near Ahrweiler and the Nürburgring race track with its racing museum "Erlebniswelt Autos-Action-Attraction".