The Portuguese River is a major river in Portugal and Spain. It is composed of three rivers: the Douro, the Ebro, and the Tagus. The Douro is a 5-letter river that flows from its source in Spain to its mouth at Porto, Portugal. The Ebro is a 4-letter river that originates in Cantabria, Spain and empties into the Mediterranean Sea. The Tagus is a 5-letter river that begins in Spain and flows through Portugal before emptying into the Atlantic Ocean. All three rivers are important to the Portuguese economy, providing water for irrigation, transportation, and hydroelectric power.