Photo: GetYourGuideThis popular full-day trip trades the city for the romantic Rhine, cruising past vineyard-clad slopes and hilltop castles between the pretty wine towns of the UNESCO-listed gorge. It is a classic, easy escape with plenty of photo stops and time to taste the local Riesling. Bring a jacket for the boat deck, and go easy at the wine stops so you can enjoy the castles and the river scenery along the way.