pixabay and 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.
This image was acquired from
Keywords from Image Description:
airport calden flughafen kassel building architecture KSF airport. en Kassel airport webandi other versions Custom marker confirmed files for migration Flugplatz KasselCalden Buildings in Kassel
Page 2017 Free-images.com. All images are Public Domain