Saarlouis Historic Fortress Town

Saarlouis was founded in 1680 on the direct order of Louis XIV of France to secure newly annexed territory along the Saar river against the Holy Roman Empire, and it remains the only town founded entirely by a French king on land that is German today. Design work was led by military engineer Sébastien Le Prestre de Vauban together with Thomas de Choisy, laying out a hexagonal, six-bastion star-fort plan considered one of the finest surviving examples of Vauban's fortification system, alongside a strict Baroque grid of streets for the civilian town within its walls. The name itself, meaning "Louis' fortress," was changed several times as the town changed hands between France, Prussia, and Germany over the following centuries, briefly becoming Saarlautern under Nazi rule before reverting to Saarlouis after 1945. Much of the original fortification ring was dismantled in the 19th and early 20th centuries as the town expanded beyond its walls, but substantial bastion sections, the Ludwigstor gate, and stretches of the moat survive and have been restored as public parkland encircling the historic core. The Großer Markt at the town's center preserves the original Baroque layout, framed by 18th-century townhouses and civic buildings that follow Vauban's original grid. Ongoing restoration since the late 20th century has stabilized surviving bastion walls and converted former military ditches into walkable green space, allowing visitors to trace the star-fort's outline on foot around the old town.