Jaca had, in 2004, 12,322 residents and is a premier tourist destination in the region for summer holidays and winter sport. Jaca was the host city of the 1981 and 1995 Winter Universiades. Its popularity for winter sports has been a motivating factor in the city's failed bids for the 1998 Winter Olympics,2002 Winter Olympics and 2010 Winter Olympics. It was again the applicant city of Spain for the 2014 Winter Olympics, but the bid failed again when it was not selected as a candidate city.
The origins of the city are obscure, but its name apparently reflects the Iaccetani, mentioned by Strabo as one of the most celebrated of the numerous small tribes inhabiting the basin of the Ebro. Strabo adds that their territory was the scene of the wars in the 1st century B.C.E between Sertorius and Pompey. The Moorish writers mention Dyaka as one of the chief places in the province of Sarkosta (Zaragoza). When it was reconquered is unknown. Ramiro I of Aragon (1035 - 1063), gave it the title of " city," and in 1063 held within its walls a council, in which, the people were called in to sanction its decrees: an early milestone in the parliamentary traditions in the Pyrenees.
The mutiny of the garrison at Jaca, demanding the abolition of monarchy and a democratic republic, December 12–13, 1930, was suppressed with some difficulty. It was an early event that prestaged the Spanish Civil War.
The Diocesan Museum of Jaca (Museum of Medieval Sacred Art) protects Romanesque and Gothic frescoes from some of the most remote locations in the district of Jaca, unsuspected until the first one was discovered in the Church of Urriés, in 1962, where it had been hidden and protected by the painted and gilded retable, or altarpiece.
The Jaca citadel is home to a colony of Rock Sparrows.