A Gnomonic Hole Sundial Between Reality and Simulation

This paper explores the integration of physical heritage visits with digital technologies through the case of the eighteenth-century gnomonic hole sundial located in the University Palace of Genoa. The study proposes a hybrid strategy combining on-site experience, panoramic photography, photogrammetric modelling, multimedia virtual tours, and augmented reality to communicate the scientific and historical value of the instrument. Since the original gnomonic hole is no longer preserved and the room currently serves other institutional functions, digital tools are used to simulate the sundial’s operation and improve public accessibility. The MultiPano platform incorporates 360° environments, texts, subtitles, audio descriptions, videos, drawings, and 3D visualizations tailored to different user needs, including remote visitors and people with sensory disabilities. QR-code activated AR content further enriches the on-site visit by showing solar ray simulations and explaining the astronomical functioning of the device. The research demonstrates how digital mediation can reactivate hidden scientific heritage while balancing preservation, accessibility, and education.