Fourth autonomy for its surface with 10 %, though one of those of minor population density, especially in Huesca. It has suffered a great rural exodus, with birthrate falls and light increase of the mortality rate, for aging especially in Teruel. Nevertheless thanks to the economic dynamism of Saragossa, the industrial activity of the region occupies the fourth part of the active population, slightly more of the half of this one in the service sector . Its unemployment index is lower than the national average.

The Kingdom of Aragon was founded by Ramiro I (1035-1063). In Roman epoch it belonged to the province of Citerior populated in the main by Iberian. The Arabs left numerous fingerprints of his civilization. In the 10th century it had been incorporated into the Kingdom of Navarre. In the 12th century joined Catalonia, is annexed to Majorca and Valencia. Its Mediterranean vocation, not only to the trade but also to the conquest, it made annex Sicily, Corsica, Cerdena, Naples.... The union link with Castile in epoch of the Catholic Kings allowed to support its organization system that later will be the seed of the Spanish Nation.

The Ebro Depression is the great structural unit and is surrounded by the Pyrenees and the Iberian System. Its average altitude is higher then that of the rest of Spain, having almost 60 % of its lands over 600 m of altitude.

Pyrenees Mountain chain : Its peaks overcome all 3000 m (Aneto, Maladeta, Monte Perdido ....) Attached to they the lowest mountain ranges or prepirenaicas they are of minor altitude (Collarada, Tendeñera, Visaurín ....).

Ebro Depression: of triangular form and with agricultural utilization. It borders in the northern part with the Pyrenees, in the southern part with the Iberian Mountain chain and in the eastern part with the Coastal - Catalan Mountain chain.

Iberian system: Stands out the peak of the Moncayo and Gúdar's mountain ranges (2024 m) and Albarracín (1830 m). More in the southern part one finds Javalambre's mountain range (2020 m).

There predominates Mediterranean continental type that includes the Ebro valley and the areas with lower heights then 1200 m. It is characterized by the irregularity in the rainfalls and an aridity that diminishes towards the region periphery. It rains in the equinoxes thanks to the Atlantic cyclones to the effect Föhn. The thermal contrasts are marked between summer and winter. The Cierzo north wind is the most important wind of the zone though also the winds of the North and Northwest are of great intensity . The major rainfalls take place in the Pyrenees, in the snow shape.
In the Iberian System the climate variations are depending on the height.

Pyrenees Mountain chain: In the low zones it predominates over the oak and the bushes, box and holly, followed by the oak and beech that alternate with the white pine. In height you can find species of cold climate as the fir, black pine and finally the pasture. In very high levels the vegetation disappeares.

Ebro Depression: The vegetation climax is the sabina accompanied of the black hawthorn, grass, broom, etc the pinegrove with the aleppo pine and others, and the carrascal with oak, kermes oak and the box principally.

Iberian system: the rockrose coexists with the brooms. From 1300 m oaks, gall oaks are whitly, oak, beech, pines (blackish, red and wild), birch, arboreal heather, ferns and bushes depending on the height.

Except the Ebro, they are short. The left margin tributaries of the Ebro are mightier, due to its glaciar origin. Low water takes place in summer and in the valley they disappeare. The principal utilization is realized by means of reservoirs (Sotonera, Tranquera, Mequinenza, The Lagoon, Moros) and channels (Imperial de Aragon, Monegros, Cinca). The Plan Bárdenas of the National Settling Institute was an initiative for extending the irrigation.