Continuing the work of our first season in the Theater of Pompey in 2002, our second excavation season (July–August 2005) revealed a layer of travertine slabs at 10.38 masl, which was probably a section of the foundation. We also investigated the area around an ancient pier, one of the pair between the excavation area and the passage under the stairs/seats that led to the Temple of Venus Victrix. By calculating the depth of the pier, we located the theater’s facade and accurately established its radius and diameter. The pier’s location showed that the widths of the arches on the facade varied. The measurements of other piers excavated by Baltard in the Largo dei Librari gave us the height of the facade arches and allowed us to calculate the dimensions of the Tuscan order that framed them and to speculate about its character and those of the two superimposed orders. Our excavation and site map (supplemented by archaeological studies of the early and middle 19th century) identify the north wing of the Pio Palace as the site of the Temple of Venus Victrix and indicate that the walls of the temple foundations are, as the Forma Urbis shows, slightly displaced toward the south and that the temple had an apse. From the two known stair positions, a comparison of the structural similarities between the Theaters of Pompey and Marcellus and from the 19th-century excavation plans of Baltard and Pellegrini, we suggest locations for the stairs to the upper floors and indicate how the different social classes could have reached their seats.