Tagus

The Tagus, known as Tejo in Portuguese and Tajo in Spanish, is the longest river on the Iberian Peninsula. It runs roughly east to west across the center of the peninsula, flowing from its springs in eastern Spain to the Atlantic Ocean at Lisbon, Portugal. The river has shaped the history, culture, and economy of the regions it traverses and remains a major source of water, irrigation, and hydroelectric power.

Course and geography

The Tagus rises in eastern Spain, near the Montes Universales in the system of the Iberian Mountains, and follows a generally west-northwest course across central Spain. It passes near major settlements such as Toledo before crossing the border into Portugal and continuing toward the Atlantic. In its lower course, the Tagus collects several tributaries and delivers water to urban areas and agricultural lands along the Tagus valley. It finally empties into the Atlantic Ocean near Lisbon.

Hydrology and use

The Tagus basin covers a large portion of central Iberia and supports a range of uses, including municipal water supply, irrigation for agriculture, and renewable energy through hydroelectric plants located on both the Spanish and Portuguese sides. In its lower reaches the river shapes urban development, most notably in Lisbon, which lies at its estuary. The river basin faces environmental and water-management challenges, including seasonal droughts and cross-border coordination between Spain and Portugal.

Historical and cultural significance

Historically, the Tagus has been a corridor for civilizations and trade in the region and has influenced the development of cities such as Toledo in Spain and Lisbon in Portugal. The river’s lower valley and estuary have been important for commerce, transportation, and cultural exchange throughout Iberian history.