This paper describes some ground-penetrating radar (GPR) results to characterize steel tanks buried in the subsoil of an urban center. Tanks were installed in the first Brazilian geophysical test site located at the Institute of Astronomy, Geophysics, and Atmospheric Science (IAG) of the University of São Paulo (USP). This paper also presents an effective procedure for removal of hyperbolic artifacts associated with GPR reflections between multiple steel tanks. One hundred sixty-five GPR profiles of , , and (shielded bistatic antennae) were measured. The work was done in two distinct places: on the geophysical test site of the IAG/USP in the city of São Paulo, Brazil, and in an area formerly occupied by a truck cleaning, refueling, and maintenance facility, located in Oscoda, northeastern Michigan, USA. Predictive deconvolution and Kirchhoff migration were first used to improve vertical and lateral resolution. To minimize the hyperbolic artifacts caused by reflections between tanks, high-pass filtering was applied to data. Then, Hilbert transforms emphasize the location of the steel tanks in an energy cross-section form. Further GPR processing, such as vertical and depth slices, were very important to improve visualization and localization of steel tanks and pipes in the subsurface.