The Roman thermal space of S. Pedro do Sul is located on the bank of the Vouga river, about 500 meters from the thermal water spring. The building, of Roman foundation (1st century AD), has maintained much of its primitive structure until today and has been classified, since 1938, as a National Monument. Its long and diversified occupation over the centuries was marked by small signs, which did not, however, prevent the initial Roman structure from prevailing. The recovery, rehabilitation and conservation project was based on the restoration of the building, proposing the minimum intervention necessary for its use and correct perception. The recovery of the most striking features of the environment from the Roman period was based on scale, light and the presence of water.