In 1579, the Academy obtained the rights to build a permanent theatre in an old fortress, the "Castello del Territorio," which had been turned into a prison and powder magazine before falling into disuse. Palladio was asked to produce a design, and despite the awkward shape of the old fortress, he decided to use the space to recreate an academic reconstruction of the Roman theatres that he had so closely studied. In order to fit a stage and seating area into the wide, shallow space, it was necessary for Palladio to flatten the semicircular seating area of the Roman theatre into an ellipse.