Preface Special issue: Monitoring and Seismic Characterization of Archaeological Sites and Structures

 The preservation of cultural heritage is a crucial issue in areas prone to seismic and other natural hazards. The major challenge in pursuing such an important objective is related to the extreme fragility of ancient monuments and buildings exposed for centuries to the ravages of time. A suitable way to successfully proceed in the preservation effort of monumental structures should be based on then integrated use of different non-invasive diagnostic techniques, aimed at understanding the geological and geotechnical features of the areas where monuments are founded and the structural characteristic of the construction itself. In this perspective a team composed by researchers of ENEA, INGV and Sapienza University of Rome has recently carried out geophysical and structural investigations on the Amphiteatrum Flavium in Rome, better known as Colosseum, which is the symbol of monumental heritage in Italy and well-known all over the world. The experimental campaign was only a preliminary analysis of the very famous archaeological site that allowed outlining the state of knowledge about the characteristics of the site and the structure and should be considered as a starting point for an in-depth investigation of the monument vulnerability. In our opinion, the benefits of such an integrated approach can steer the political and social choices related with the preservation of the cultural heritage at National or European level.