The Segre is a river tributary to the Ebro (Ebre in Catalan) with a basin comprising territories across three states: France, Andorra and Spain.
The river Segre, known to Romans and Greeks as Sicoris, and to the Arabs of Al-Andalus as Nahr az-Zaytūn has its sources on the north face of the Pic del Segre or Puigmal de Segre in the French department Pyrénées-Orientales (historically the comarca of Alta Cerdanya), in the Catalan Pyrenees. It follows a western direction all along the Cerdanya (Cerdagne) Valley, and crosses the town Saillagouse, the Spanish exclave Llívia and Bourg-Madame.
It enters Spain at Puigcerdà and continues west until La Seu d\\\\\\\'Urgell, where it meets the Valira River coming from Andorra.
From this point it adopts a south-western course across the pre-Pyrenees (with several dams along its gorges) and the western plains of Catalonia.
It passes through Balaguer, Lleida and flows into the Ebro at Mequinenza.
Among its tributaries: Valira (from Andorra), Noguera Pallaresa, Noguera Ribagorzana, Cinca.
