Built for an initiative sponsored by Piacenza City in 1342, The Fortress was reinforced and finished by Luchino Visconti in 1347.
It is an impressive building made by bricks, with a defensive nature in a strategic and dominant position on the surronding valley.
In addition the hight tower, soaring on the square, was a defence tool from the enemies and a tools for controlling the citizens.

The Fortress, build on a old roman set up (called Castrum Quadratum), presents a unusual shape.

The building is surronding by a double wall: the smallest, but the largest, covers the two levels, where the soldiers are used to live and where, in case of emergency, the citizens could found a safe place; the highest wall, perpendicular to the other, was reservated to the command of the garrison.

The hight tower, the best observation point, was build for a defence and military goal and wasn't a residential place.
In XIX and XX centuries, until 1960, the Fortress was a prison.

In 1985 in Castell'Arquato were set a lot of different scenes of the film "Ladyhawke" with Michelle Pfeiffer, Rutger Hauer and Mettew Broderick.