The folio comprises drawings, and accompanying captions, in pen and sepia ink, which can be dated between 1487 and 1490. The detail of the drawing shown here is to be found at bottom on the right-hand side. It illustrates a plan view and a perspective of a corner of castle with a quadrangular jutting structure. Top left is a portion of a drawing depicting the plan of a stronghold tower, and a drawing of a centrally-planned temple (not visible here); top right is a bird's eye view of the flank of a fort which, along with its moat and counterscarp wall, is also shown in cutaway view. The drawings probably date from different periods.