Ardila

The Ardila (; ) is a river of

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

and

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

and a

tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage ...

of the

Guadiana The Guadiana River (, also , , ), or Odiana, is an international river defining a long stretch of the Portugal-Spain border, separating Extremadura and Andalusia (Spain) from Alentejo and Algarve (Portugal). The river's basin extends from the e ...

. Its length is . A portion of the river forms the

Portugal–Spain border The Portugal–Spain border, also referred to as "The Stripe" ( es, La Raya, pt, A Raia, gl, A Raia, mwl, La Raia), is one of the oldest borders in the world. The current demarcation is almost identical to that defined in 1297 by the Treaty of ...

. Rivers of Spain Rivers of Portugal International rivers of Europe Portugal–Spain border Tributaries of the Guadiana River {{Beja-geo-stub