The Isábena is the principal

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''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 into which they ...

of the river

Ésera The Ésera () is a tributary of the Cinca in the High Aragon. It is part of the valley of the Ebro and its drainage basin. Its etymology is Celtic and it is cognate with several European rivers: Isar, Jizera, Isère, Isel, IJssel, and Eisack ...

, itself a tributary of the Cinca, which flows into the

Ebro The Ebro (Spanish and Basque ; , , ) is a river of the north and northeast of the Iberian Peninsula, in Spain. It rises in Cantabria and flows , almost entirely in an east-southeast direction. It flows into the Mediterranean Sea, forming a de ...

and thence to the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

. Its head is 2,400 metres above sea level at a place called Es Sebollés, between the peaks Gallinero and Cibollés in the

Pyrenees The Pyrenees are a mountain range straddling the border of France and Spain. They extend nearly from their union with the Cantabrian Mountains to Cap de Creus on the Mediterranean coast, reaching a maximum elevation of at the peak of Aneto. ...

High Aragon Alto Aragón (literally, ''Upper Aragon'' or ''Highlands of Aragon'' in English; compare Upper Navarre, Upper Rioja) is the northernmost territories or highlands of Aragon, flanking the Pyrenees and includes the Aneto Mountain, the highest pea ...

. Its valley lies primarily in the comarca of Ribagorza. The Isábena flows between the massive

El Turbón El Turbón is a mountain massif of the Pre-Pyrenees, located in the province of Huesca, the most northerly province in the autonomous community of Aragon, Spain. This long mountain is aligned N - S. It is fairly easy to climb El Turbón, but it ...

mountain and the Mountains of Sis range.Inst. Tecnologico Geominero de Espana, 1994, ''Mapa Geologico de la Peninsula Iberica, Baleares y Canarias'', scale 1:1M

References

Rivers of Spain Rivers of Aragon {{Spain-river-stub