Recto: "Libro Primo, Chapo Quarto..." (Vitruvius, Book 1, Chapter 4); Verso: The Fortification of City Walls (Vitruvius, Book 1, Chapter 5). 1530 - 1545

This pen-and-ink drawing by the Sangallo family, dating from 1530-1545, depicts a detailed, bird's-eye view of a fortified city wall. The drawing, titled "Recto: 'Libro Primo, Chapo Quarto...' (Vitruvius, Book 1, Chapter 4); Verso: The Fortification of City Walls (Vitruvius, Book 1, Chapter 5)", uses a technical, almost scientific approach to illustrate the architectural design, including the use of perspective to accurately render the wall's structure. The drawing is a testament to the Sangallo family's expertise in Renaissance architecture and fortification, showcasing their attention to detail and mastery of technical drawing.