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:
Fotothek df tg Architektur Festungsbau Ravelin Redan Grabenschere Bastion Lnette . Scan Deutsche Fotothek dftg color MIKCenter Berlin GmbH Fig VIII Nrnberg Befestigungsanlagen Papier Kupferstich cm Architektur Festungsbau Ravelin Redan Grabenschere Bastion Lnette Flanke Contregard Wall ppn Druck Deutsche Fotothek gefrdert