Sierra de Gratal
The Sierra de Gratal is an Aragonese mountain range that lies in the first foothills of the Pyrenees and is oriented from west to east. To the west, the Sierra de Gratal is separated from the Sierra Caballera by the gorges of the Salado River, a tributary of the Sotón, in the catchment area of the Gállego River . To the east, the Foz de San Clemente , excavated by the Isuela River (a tributary of the Flumens in the Alcanadre basin ), separates the Sierra de Gratal from the Sierra del Águila.
The Sierra de Gratal is located in the comarca Hoya de Huesca in the northeast of the city of Huesca . One of the main heights, the triangulation point , is the Peña Gratal, with a height of 1,543 meters. The highest point is the Pico de la Calma , which lies on the north slope of the mountain at the foot of the Arguis reservoir and is 1,581 meters high. On the southern slope, the Pico Gratal is the second height of the mountain range at 1,567 meters. At 1,528 meters, Pico San Julián is the fourth peak with a height of more than 1,500 meters.
The tributaries on the right bank of the Isuela, the Venia and its tributaries and the tributaries of the Salado on the left bank collect the waters of the Sierra de Gratal.
The area of the Sierra de Gratal is divided between the municipalities of Arguis , Nueno and Lierta, while the cities of Nueno, Arascués and Lierta lie at the foot of the southern slope of the Sierra de Gratal.
