Hohenasperg (fortress) built
1535 CE.
Shown on the map at 48.910°, 9.138°.
Hohenasperg, located in the federal state of Baden-Württemberg near Stuttgart, Germany, of which it is administratively part, is an ancient fortress and prison overlooking the town of Asperg. It was an important Celtic oppidum, and a number of very important "princely" burials are close by, in particular the Hochdorf Chieftain's Grave.
Text from the Wikipedia article Hohenasperg, licensed CC BY-SA 4.0.