The remains of the fortress can be visited
Fortress Magdeburg-Fort VI

Fort VI in Magdeburg is a relic of the Magdeburg Fortress, which from the early 18th century until 1912 was among the strongest Prussian defensive structures.
History+
Magdeburg's first fortifications were established as early as the 13th century. Between 1450 and 1550, the facilities were significantly expanded due to the development of firearms, including a second city wall and the fortification of the Elbe front. These reinforcements proved effective during the sieges of 1550/51 and 1629. During the Thirty Years' War, the fortress was expanded under Swedish command, but neglect of the southern front led to its capture by imperial troops in 1631 and the demolition of its structures. From 1666, Elector Frederick William ordered its reconstruction, which in several phases until around 1740 resulted in one of Prussia's strongest fortresses. Nevertheless, Magdeburg surrendered without a fight to Napoleonic troops in 1806.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Oben22 / Public domain via Wikimedia Commons
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: 52.1538, 11.6112