Jaca (hä`kä), town (1990 pop. 10,874), Huesca prov., NE Spain, in Aragón, in the Pyrenees (alt. c.2,700 ft/820 m), near the French border on the Aragón River. A communications center and an episcopal see, it is a processing center for lumber and for the farm products of the fertile Aragón valley. After its recapture from the Moors it was (11th cent.) the cradle of the Aragonese kingdom. Huesca, taken in 1097, replaced it as the capital. Jaca has ancient walls and towers and a Romanesque cathedral (11th–15th cent.).