Tagus

The first one in Top 10 Longest Rivers in Portugal that Toplist would like to introduce to you is Tagus. The Tagus is the Iberian Peninsula's longest river. The river begins in the Montes Universales in central-eastern Spain and travels 1,007 kilometers (626 miles) west, with two major south-west parts, until emptying into the Atlantic Ocean near Lisbon. Its drainage basin is 80,100 km2 (30,927 sq mi), second only to the Douro in the peninsula. The river receives a lot of traffic. Several dams and diversions provide potable water to central Spain and Portugal's major population centers, while dozens of hydroelectric units provide electricity. It has a very constrained path between dams, but after Almourol, Portugal, it has a vast alluvial valley that is prone to floods. Its outlet is a wide estuary that leads to Lisbon, Portugal's principal port and city.

All of the major tributaries are on the right bank, which lies to the north in this area. The river flows 716 kilometers (445 miles) through Spain, 47 kilometers (29 miles) along the border between the two countries, and 275 kilometers (171 miles) through Portugal.

Tagus river runs through Aranjuez, Toledo, and Talavera de la Reina in Spain, and Abrantes, Santarém, Almada, and Lisbon in Portugal, in that order. Madrid, Spain's capital, is located in the upper drainage basin.

Length: 1,007 km (626 mi- shared with Spain)