The Douro River is a historically significant river of the Iberian Peninsula, creating a magnificent waterway for cruise ships. The Douro River cruises run from Porto, Portugal to Vega de Terron, Spain. Most cruises are round trip from Porto. The most eminent structure on the river, the Dom Luis I Bridge, stretches to 951 feet long. You get a variety of Portugal and Spain on Douro River Cruises, meaning excellent Paella from Spain and Port wines from Portugal, along with Flamenco dancers and Portuguese pingo (like espresso).