The remains of the fortress can be visited
Fortress Magdeburg-Kavalier V
Kavalier V is a section of the former Fortress of Magdeburg. The remnants of this building are located in Magdeburg, Saxony-Anhalt, Germany.
History+
Magdeburg's initial fortifications date back to the 13th century. Between 1450 and 1550, the facilities were expanded to meet the new demands of firearms. This included the construction of a second wall, a new moat, and the initial fortification of the Elbe front. Despite these reinforcements, imperial troops managed to capture the city in 1631 during the Thirty Years' War, as the southern front had been neglected. The fortress was subsequently razed.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Magdeburg_Kavalier_5.JPG
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 52.1265, 11.6207