“Forgetting” all about Richard Meier’s existing setting for the Ara Pacis altar, the project proposes a radical departure: portions of roadway not absolutely essential to traffic are eliminated, freeing space for a concave plaza that slopes down to the mausoleum from the street; a section of the riverside drive is replaced by a tunnel; the Ara Pacis is moved from its current level to that of the Via Ripetta; traces of the port and the buildings that stood along the riverbank, demolished when the retaining walls were built, are rediscovered. These operations restore the rich texture of the original topography, revealing the complexity of the ensuing transformations while linking the plaza to the Tiber, so as to renew the ties between the city and its river.