The project, started in 2003, explored the interrelationship of commercial, religious and monumental space in the area between the temple of Castor, the Oratory of the Forty Martyrs, and the Domitianic Aula; and along the Vicus Tuscus and in the Horrea Agrippiana. In the Horrea, two trenches were opened on the west and south sides, where original stratigraphy remained undisturbed below levels reached by early 20th century clearance work. Between the temple and the portico of the Domitianic Aula we focused on understanding the phasing and function of structures already investigated by Boni, and investigating intact stratigraphy untouched by him. The campaigns yielded a wealth of data, currently being prepared for publication. Among the main results are: 1) evidence for early occupation W. of the Oratory of the Forty Martyrs and S of the Temple of Castor (Archaic floors, post holes, refuse pits; subsequent occupation with capellaccio structures). 2) Two phases of Republican structures in opus quasi reticulatum under the W range of the Horrea Agrippiana. 3) Evidence for a large monumental building with ashlar basal courses on concrete foundations, to the W of and partly underlying the Oratory of the Forty Martyrs. 4) Pre-Domitianic foundations and drains underlying the N portico of the Domitianic aula (Augustan housing and at least two phases of Julio-Claudian monumental structures). These remains are not reconcilable with the theory that Fragment 18a of the marble plan of Rome depicts a pre-Domitianic layout of the area. 5) A concrete-cased drain and overlying concrete feature between the Domitianic aula and the Temple of Castor, abutting the latter. 6) Evidence of late occupation of the Horrea, consisting in wooden structures (cuttings on paving stones of the courtyard for posts), building activity in late antiquity (raised floor level), and burnt destruction layers with a t.p.q. of 588-602. (Annalisa Marzano, Andrew Wilson)