Nowadays only few examples of the attractive classical stone architecture remain standing, since the historic settlements of the populations which have built them, were often located in areas of severe seismicity. The interest of the scientific community in the conservation of these important historical structures is in continual increase. The main difficulty resides in improving the seismic strength by preserving the cultural heritage at the same time; in summary non-invasive strengthening methods are requested. The suggested possibility is the Tendon System: a passive structural control...