The development and dissemination of ICT have also influenced the cultural heritage sector. In the last decade, for this reason and not only, the way of doing scientific research, documentation and enhancement has quickly changed, to such a degree to question the real benefits brought by the digitization and virtualization of the historical buildings, in the fields just mentioned.

The paper is part of a research field linked to the analysis of the metric and formal reliability of 3D integrated surveying and digital modeling of architectural heritage, and to the critical evaluation of the photogrammetry and laser scanning as tools for the deep knowledge and for the dissemination of the object of study.

In particular, the focus is on the majestic Aragonese Castle of Ischia –whose origins date back to the fifth century BC, located in the eastern part of the island, on an area of over 5 hectares– and on the ruins of the Cathedral of the Assumption, of the fourteenth century, preserved inside.

Starting from particular analysis and coming to general methodological considerations, the research had different objectives: comparing qualitatively and quantitatively the goodness of image-based and range-based surveys of single environments, determining the spatial location of some volumes compared to others, analyzing the “Castle-Cathedral system” through the development of virtual reality applications built from photo-modeling and laser scanning at the urban scale.