In the summer of 1502, Cesare Borgia appointed Leonardo da Vinci for his engineering expertise. His assignment was specific and concerning with military architecture: he was expected to “see, measure and do good estimation”. The Codex L, a small notebook conserved in the Library of the Institute of France, show the results of the survey of the city walls of Cesena and Urbino.
This paper deals with the documentation and digital survey of fortifications in the historic city of Piombino. During the Renaissance the fortified perimeter of the city was considerably enlarged, both because of the will of the Lords of Piombino, the Appiani, to build a fortified citadel, deeming the previous urban palace inadequate for the ruling family, and to improve the defenses by land with the construction of a rivellino in front of the north door and of a fortress to the east.