Guadiana River
Rio Guadiana
Guadiana river.jpg
The Guadiana River in the area around Serpa, Portugal
Rio guadiana.svg
About 83 percent, 55,000 square kilometres (21,000 sq mi), of the River Guadiana watershed is in Spain; the rest is in Portugal
EtymologyArabic derivative of Wādī + Ana, meaning "River Ana"
CountryPortugal, Spain
Physical characteristics
SourceOjos del Guadiana
 ⁃ locationVillarrubia de los Ojos, Castile–La Mancha, Spain
 ⁃ coordinates39°7′36″N 3°43′36″W / 39°7′36″N 3°43′36″W / 39.12667; -3.72667
 ⁃ elevation608 m (1,995 ft)
MouthGulf of Cádiz
 ⁃ location
Vila Real de Santo António, Algarve, Portugal
 ⁃ coordinates
37°10′12″N 7°23′37″W / 37°10′12″N 7°23′37″W / 37.17000; -7.393611,500 m3/s (53,000 cu ft/s)
Basin features
 ⁃ left
 ⁃ right

The Guadiana River (ə/, also US: ə/,[1][2] Spanish: [ɡwaˈðjana], Portuguese: [ɡwɐðiˈɐnɐ]), or Odiana, is an international river defining a long stretch of the Portugal-Spain border, separating Extremadura and Andalucia (Spain) from Alentejo and Algarve (Portugal). The river's basin extends from the eastern portion of Extremadura to the southern provinces of the Algarve; the river and its tributaries flow from east to west, then south through Portugal to the border towns of Vila Real de Santo António (Portugal) and Ayamonte (Spain), where it flows into the Gulf of Cádiz. With a course that covers a distance of 829 kilometres (515 mi), it is the fourth-longest in the Iberian peninsula, and its hydrological basin extends over an area of approximately 68,000 square kilometres (26,000 sq mi) (the majority of which lies within Spain).


The Guadiana drainage basin in the Iberian peninsula

The Romans referred to the river as the Flumen Anas, the "River of Ducks". During the Moorish occupation and settlement, the name was extended and referred to as Wadi Ana (wādī being the Arab term for "river"), later passed on to Portuguese and Spanish settlers as the Ouadiana, and later just Odiana. Since the 16th century, due to Castilian influences, the name has slowly evolved to take on the form Guadiana, a cognitive variation that developed from many Moorish-Arab river place-names using the prefix guad- (such as the rivers Guadalquivir, Guadalete, Guadalajara or Guadarrama).