The fortified island of Ortigia: rediscovering a lost heritage through digitalisation and historical memory

Located on the eastern coast of Sicily, Syracuse represents a remarkable example of a stratified city whose morphological evolution reflects centuries of historical, cultural, and urban transformations. One of the most significant elements of this process is the defensive system. Starting from the isthmus, it transformed Ortigia - the city's oldest area - into a fortified island of strategic impregnability. Over time, the development of the fortification system played a crucial role in defining the island's historical and cultural identity, protected by a complex network of bastions, monumental access gates, and military works. This study focuses on the digital volumetric reconstruction of these fortifications, which underwent profound modifications over the centuries until their definitive dismantling at the end of the nineteenth century. The digitisation of the lost cultural heritage was based on the analysis of different archival sources, historical cartographic documents, and iconographic materials from various historical periods. These were complemented by photogrammetric surveys of fragments no longer in their original locations. The integration of these sources with advanced digital modeling technologies enabled the three-dimensional reconstruction of disappeared or transformed defensive structures, providing an effective tool to valorize and protect the urban heritage. This ‘virtual restoration’ not only allows a clear visualization of the historical transformations but also transmits the the memories of the city to future generations. The integrated operational methodology and the historical research using digital tools enables us to read the invisible traces of the past. Only through technology is it now possible to explore Ortigia's lost fortification system.