CASTILLO DE LA BALLESTA – ARDISA (R)
It is one of the few Romanesque castles built on a plain, in order to control an important north-south communication route. Building of Sancho Ramírez towards 1083, of which the central tower of 7m of side and four plants in its origin is conserved, although now they are five, remade most in principles of S. XIII. The residential building that surrounds it, about 20m on the side, late Gothic from the XIV-XV centuries, serves as a buttress for the tower. All this was surrounded by a wall built in sillar stone of 160m length partly crenellated.
See its description in Románico Aragonés