This volume is the second in the ARGU series about the Roman deserted town of Ammaia, in Portugal. The first, titled Ammaia I: The Survey: A Romano-Lusitanian townscape revealed, focused on the results of a total survey of the urban and suburban areas, while this second volume intends to disseminate results of almost two decades of archaeological excavations in the ancient town center. Several international teams excavated in the most vital sectors of the town - forum, public baths, and main gate - and present here the discovered structures, including a study of artifacts from all sectors, as a major contribution to the archaeology of Roman Lusitania.