In Portugal, the Douro River is a popular Viking River Cruises destination. The third-longest river in the Iberian Peninsula after the Tagus and Ebron, the Douro is 557 miles and is navigable in Portugal by light rivercrafts.
With its mountains and hillsides covered in vineyards and villages with their bright orange-tiled rooftops, it is ideal for anyone wanting to relax and enjoy the scenery as well as visit tourist destinations near the river.