The 164-passenger AmaReina journeys along the Danube River, anchoring at popular ports such as Vienna and Salzburg. The interiors are spacious — most staterooms have both a French balcony and a step-out balcony — but the highlights are al fresco. The chairs on the top deck (where you can also have lunch) provide sweet spots to soak up the sun, and the pool with swim-up bar is a refreshing spot after a walk through the cobblestoned streets of Dürnstein or Linz, Austria.