out of copyright (called public domain in the USA), hence royalty-free stock image for all purposes usage credit requested Please do not redistribute without permission, since running this site is expensive.
Plan of the mediaeval manor-house that’s illustrated in Fig. 25.
You can get a version of this image without the watermark at the lower right corner by requesting it here; The images are watermarked to help people find where they came from if they get reposted to blogs or other sites. Images under 1200 pixels on a side
are still free, although I will ask for a donation :-)