The fort has an area of 320.000 m2 (550.000 m2 if is included the space of his "glacis"). Due to these epic proportions it is de largest monument in Catalonia and the biggest fortified fortress in Europe.
It was built to reinforce the frontier after the loss of ‘Rosillon and Cerdenya’. The castle is placed on a hill, due to its strategic advantage and due to the magnificent panoramic views.