These maps are the results of the research, focused on the complex east of the Baths of the Porta Marina, is part of a research project on the coastal area of Ostia carried out by the Centre Camille Jullian, CEREGE and MAP-CNRS in collaboration with the Archaeological Park of Ostia Antica. The integrated study of geophysical prospections (electrical resistivity tomography, magnetic field mapping, electro-magnetic survey), satellite images and topography allowed to define the characteristics of a large complex covering an area of approx. 15,000 m2. In particular, the presence of a large open area, flanked by a building with a basilical plan, makes it possible to recognize the structures of a forum. The location at short distance from the ancient coastline allows to identify the "Aurelian’s forum" and the praetorium known from the Historia Augusta.