This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Heidelberg Castle redoubt. en Heidelberg Castle Germany redoubt on the southeastern corner of the castle It was erected most likely in by Johann Casimir The redoubt is meters long meters wide and meters high The picture shows the southern side of the building The five openings are only light gaps because this side was free