The latest advances in the architectural survey and 3D reconstruction have produced new technologies and methodologies to enhance cultural assets and improve their accessibility. The possibility of virtually visiting a place of historical and cultural interest is often the only way to have access to it. This can happen for various reasons: users' disabilities, temporary site closure, assets located in remote and inaccessible places, and assets destined to disappear over time. Fortunately, new Geomatics and Computer Science technologies allow the virtual reconstruction of entire archaeological and monumental sites with high levels of accuracy. Considering the technologies related to VR, online virtual fruition techniques were recently adopted, using the open source WebGL JavaScript libraries. These libraries allow users to virtually explore the virtual model employing web browsers without installing any client-side applications. The work presented adopts these technologies. It falls within the VASARI project, whose goal is to create a single digital platform for the enhancement, use, and management of the Italian artistic heritage. In particular, the described work concerns the survey, 3D reconstruction, and web visualization of the archaeological site of the Inquisition Prisons located within the monumental complex of Palazzo Chiaramonte in Palermo, known as the "Steri" and today the headquarters of the Rectorate of the University of Palermo. The adopted workflow and encountered issues during implementation will be described.