Rotunde, building in Hann. Münden, Germany

The Rotunde is a former Zwingerturm, a round bastion tower of the medieval town fortification in Hann. Münden. It was built from 1501 under Duke Erich I as an outer bastion for the Oberes Tor and has a diameter of 17 meters. The round roof was rebuilt and covered with slate during the 1985–1986 restoration.

The Rotunde was completed in 1546 under Duke Erich I as a guard tower for the Oberes Tor, the main southern entrance to the medieval city. After the main gate was demolished in 1776, it lost its military purpose and was later used as brewery storage and for hearse wagons before being converted into a memorial for war casualties in the twentieth century.

The Rotunde has served as a war memorial since 1937, when a monument to the dead of the First World War was inaugurated inside; it was later extended to the dead of the Second World War. In 1966 a memorial for the victims of National Socialist tyranny was added to the exterior. The round interior is used for commemoration rather than exhibition.

The building is open year-round for outside viewing and can be easily reached via Lange Street, with parking at Feuerteich nearby. Access is partly possible, though the paved path can be uneven, and wheelchair access is limited to certain areas only.

The Rotunde kept its round shape but lost its companions: the gate beside it was demolished in 1776 and the small defensive tower in 1847. In 1966 a memorial to the victims of National Socialist tyranny was mounted on its exterior, joining the war memorial inaugurated inside in 1937. A 1985–86 restoration costing 880,000 DM rebuilt the round roof and covered it with slate.