Festivities of Ansó Activity · Ansó, La Jacetania, Huesca Image of Ansó, not of the place itself. Ansó's festival is held in the town where in 1375 six good men, led by the mayor Sancho Gracia, handed down, in the atrium of the church of San Pedro, the ruling that settled the pasture dispute between the valleys of Roncal and Barétous, the origin of the tribute of the three cows. Photo: rjime31 (CC BY-SA 2.0) What to see and do in Ansó