Drawing of a four-ramp stairway system
Where: Manuscript B, folio 47.r Year: 1487-90

The sepia ink and pen drawing, probably dating from between 1487 and 1490, was made with the transparent-body technique, which enhances the function and use of the stairway. As stated in the note, the building was almost certainly destined for military use and was included in the relief model of the ideal city for purely visual purposes, this allocation not being the intended one.