The Salzburg Fortress Museum, atop a steep climb, is one of the most visited museums in Austria. During its daily operation, the museum was redesigned and a long-lasting exhibition with well thought-out routes and purist design principles was put in place. The exhibition provides a tour of thirteen rooms and illuminates the rich history of the castle and its inhabitants. The challenging accessibility of the fortress provided the starting point for the development of a modular approach to the exhibition design.