The Isábena is the principal

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 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 The IJssel ...

, itself a tributary of the

Cinca Neonatal-onset multisystem inflammatory disease is a rare genetic periodic fever syndrome which causes uncontrolled inflammation in multiple parts of the body starting in the newborn period. Symptoms include skin rashes, severe arthritis, and chr ...

, which flows into the

Ebro , name_etymology = , image = Zaragoza shel.JPG , image_size = , image_caption = The Ebro River in Zaragoza , map = SpainEbroBasin.png , map_size = , map_caption = The Ebro ...

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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

. 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 (; es, Pirineos ; french: Pyrénées ; ca, Pirineu ; eu, Pirinioak ; oc, Pirenèus ; an, Pirineus) is a mountain range straddling the border of France and Spain. It extends nearly from its union with the Cantabrian Mountains to C ...

High Aragon Alto Aragon (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 peak in ...

. Its valley lies primarily in the comarca of Ribagorza. The Isábena flows between the massive El Turbón mountain and the

Mountains of Sis The Mountains of Sis ( ca, Serra de Sis, or ''Serra del Cis'') ( es, Sierra de Sis) is a long mountain range of the Pre-Pyrenees. They are located between the valleys of rivers Isábena and the Escales Reservoir, Noguera Ribagorzana, in the Riba ...

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