Defending the Venetian Lagoon: Digital Reconstruction of the Early Modern Fortress at the Lido

Since the 13th century, the Lido inlet—strategically positioned between the Adriatic Sea and the Venetian lagoon—served as Venice’s principal stronghold for the defence of the capital. Two medieval castles, Castel Vecchio at the northern tip of the Lido and Castel Nuovo on the opposite island of Sant’Andrea, guarded the entrance to the city’s main port and defined the area known as Do Castelli. Amid the mounting Ottoman threat in the Mediterranean, this fortified zone became the focus of the Republic’s increasingly ambitious program to reorganise, modernise, and expand the lagoon’s defences in response to evolving siege warfare. While scholarship has largely concentrated on the construction of Fort Sant’Andrea, far less attention has been devoted to its counterpart, the fortress of San Nicolò, now largely demolished. Conceived through a protracted and complex series of construction campaigns, the fortress involved some of the leading figures in Venetian military architecture who for decades debated the most effective strategies for defending the Serenissima’s last outpost before the city. Building on recent archival, cartographic, and iconographic discoveries, combined with an integrated 3D survey, this paper examines the long-term history, strategic configuration, and architectural character of a defensive outpost that epitomised the transition from medieval to early modern Venetian fortification. Using interoperable GIS-based HBIM models, the ERC "Venice’s Nissology" research group has digitally reconstructed the fortress as it appeared in the mid-17th century, tracing its main construction phases and innovative design features, thereby reviving a form of military architecture that has largely disappeared.