Fort Thüngen — known locally as the Three Acorns for its three distinctive round towers — is one of the best-preserved remnants of the city's formidable fortification system. Built in 1732 on Vauban's earlier earthworks, it now houses the Musée de la Forteresse, dedicated to the history of the Luxembourg fortress, and stands next to the striking Musée d'Art Moderne Grand-Duc Jean (Mudam) designed by I.M. Pei.
Fort Thungen
Fortress museum in Luxembourg's iconic Three Acorns tower