Survey, archaeoastronomy and communication: the Mausoleum of Galla Placidia in Ravenna (Italy)

The Mausoleum of Galla Placidia (built pre-450), is one of Ravenna‟s UNESCO protected monuments, renowned worldwide for the extraordinary mosaic decorations that cover its internal surfaces. The famous starry vault profoundly engages and inspires the observer. Its accurate representation of the real sky has been analysed and described, as has its mystical and symbolic meaning in relation to the iconographic tradition of the time. Archaeoastronomical research was carried out on the building by Giuliano Romano, who measured its orientation. The azimuth value of 180.2° highlights a north-south bearing, unique among the other Byzantine buildings in Ravenna. This paper also examines other architectural elements beyond the orientation, with particular attention paid to the building‟s small slit windows, investigating their possible archaeoastronomical significance. A functional 3D model was developed from the archaeoastronomical analysis data to display the original morphology of the building (the floor was about 140 cm lower due to subsidence), and astronomical phenomena, and to provide a multimedia way of communicating the scientific content produced. This final part of the contribution forms part of the trials conducted by the research group into interactive and noninteractive multimedia communication based on virtual models as an edutainment tool for the enjoyment of cultural sites and artefacts.