The Tagus River, also known as the Tejo River, is the longest river in the Iberian Peninsula. This majestic river flows over 1,000 kilometers from its source in Spain to the Atlantic Ocean in Portugal. Along the way, it passes through some of the most beautiful landscapes in Europe, including Madrid, Toledo, and Lisbon. In Portugal, the Tagus River is often called "Rio Tejo" and is a major source of water for the capital city of Lisbon. Other synonyms for the Tagus River include "Tajo" (in Spanish), "Rio Tago" (in Portuguese), and "Tago" (in Latin).