european jewels (2026) budapest to amsterdam | 15 days from exotic budapest, “queen of the danube,” to imperial vienna, “city of waltzes,” to the sky-high spires of cologne’s gothic cathedral—centuries of intriguing... ships: river duchess, s.s. beatrice countries: austria, germany, hungary, netherlands rivers: danube, main, rhine 4.6/5 (647 reviews) from $6,649 per person view itinerary dates & pricing