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.
PSM Sustaining wall of masonry. Sustaining wall of masonry archive org Popular Science Monthly Volume author PDold Extracted image from book to grayscale cropped whitespace ineuw archive org Popular Science Monthly Volume Popular Science Monthly illustrations Lithographs of Greece
Page 2023 Free-images.com. All images are Public Domain