An extensive geological, geotechnical and geophysical investigation was performed in L'Aquila city centre to restore Palazzo Centi, a historical building, damaged by the April 6, 2009 L'Aquila earthquake. This site investigation consisted of punctual and linear tests that allowed to define a detailed 3D model of the subsoil, irregularly affected by some peculiar conditions and characterized by low and variable values of the shear wave velocity V S in the near surface volume. In particular, the variable thickness of the upper fine-grained residual soils probably determined different ground motion amplifications during the main shock.