At the beginning of the 17th century, the citadel of Saint-Tropez was only a military tower built on the Colline des Moulins (Mills' Hill) from 1602 from plans by Raymond de Bonnefons, a military engineer of King Henry IV of France. A few decades later, surrounded by a large defensive wall to protect it against possible invaders, it became the keep of a genuine citadel. It was occupied for almost fifty years, from 1958 to 2002, by a naval museum before being restored and upgraded to accommodate the Maritime History Museum inaugurated on July 24, 2013.