Sail Only the Scenic 65 km UNESCO Gorge (Rüdesheim/Bingen to Koblenz)
Do not take a multi-day boat from Frankfurt or Cologne—90% of the castles cluster along the 65 km Upper Middle Rhine Valley between Rüdesheim/Bingen and Koblenz. The single best segment is sailing downstream (northbound) from Rüdesheim or Bacharach to St. Goar or Boppard (1 hr 40 min to 2 hr 15 min on Köln-Düsseldorfer / KD steamers, €24–€32; 20% discount when showing a valid DB train ticket or German Rail Pass).
Must-Visit Rhine & Moselle Castles
- Marksburg (Braubach): The only medieval hilltop castle on the Middle Rhine never destroyed in battle (€11 guided tour).
- Rheinfels Castle (St. Goar): Dramatic fortress ruins directly opposite the Loreley cliff.
- Burg Eltz (Moselle Hills): Held by the same family for 34 generations since 1157, tucked inside a forested valley near Moselkern/Hatzenport (€14 admission).