The main results of a campaign of experimental dynamic tests involving three important monuments of Rome, the Colosseum, the Traian Column and the Aurelian Walls are presented in this paper. The structural dynamic response due to ambient excitation and to impact force tests was investigated. The damage risk because of the vibrations induced by road and railway traffic was assessed according to international standards. Natural frequencies and mode shapes were determined and compared to numerical ones, which were obtained by a finite element model. Measuring the evolution of these quantities, which are representative of the structural conditions, allows for health monitoring of monuments.