摘要:The study conducted Oratory Byzantine catacombs of Saint Lucia in Syracuse comes from the observation of the precarious condition of the underground funerary complex from the point of view of the static structures, which have undergone several alterations over the centuries due to landslides, blockages, collapses and subsequent excavations, conservation of the frescoes found that as a result of survey campaigns that have occurred intermittently on the monument. These difficulties have conditioned the public opening of only a part of the catacombs -la region A and the Oratory of the Forty Martiri- leaving hidden the community many significant spaces including the Oratory. The research will then, through the survey instrument with laser scanner, acquire a geometric-formal documentation of this important area through a 3D model on which to investigate aspects of a static nature, geological, material, historical, archaeological, necessary for a proper design of future interventions for the protection and consolidation of the catacomb. In fact, the 3D model obtained is a virtual copy of the recorded space through which it is possible to speculate on some design and physical environmental conditions of the sites, such as lighting and ventilation, and on some solutions distribution-functional, providing also a possible model for 3D navigation allows the virtual tour of the places underground. The location of the site, the distribution of the planimetric and static environmental conditions represented in research critical issues to be addressed in the survey phase of underground sites, providing for the research group of the fixed points on which to structure a possible protocol operating acquisition, integration, management and processing of the acquired data subject to change.