The Reduit Tilly is located in the inner fortress ring
Museum
Fortress Ingolstadt-Reduit Tilly

The Reduit Tilly in Ingolstadt, Bavaria, forms the central structure of the Tilly-Veste, which once served as a bridgehead.
History+
The origins of the Ingolstadt Fortress date back to the Middle Ages. From 1537, Duke Wilhelm IV had the city expanded into a state fortress. After the Thirty Years' War, the existing works were reinforced and expanded between 1654 and 1662 under Christoph Heidemann. During the War of the Spanish Succession and the War of the Austrian Succession, the fortress played a role, but in 1800, it was surrendered without resistance to Napoleonic troops and subsequently destroyed.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 48.7609, 11.4312