Bischofstein Castle : Across the river from the municipality of Burgen is this 13th - century castle but was reconstructed and now serves as a retreat centre for the Fichte Gymnasium in Krefeld .
This 13th - century castle was destroyed during the Nine Years ' War .
Bischofstein Castle : Across the river from the municipality of Burgen is this 13th - century castle , which was destroyed during the Nine Years ' War , but was reconstructed and now serves as a retreat centre for the Fichte Gymnasium in Krefeld .