The Jewish and Christian inhabitants of twelfth-century Rome viewed the urban landscape of their city through the lens of its ancient past. Their perception of Rome was shaped by a highly localized topography of cultural memory that was both shared and contested by Jews and Christians. Our reconstruction of this distinctively Roman perspective emerges from a careful juxtaposition of the report of Benjamin of Tudela’s visit to Rome preserved in his Itinerary and various Christian liturgical and topographical texts, especially those produced by the canons of the Lateran basilica. These sources demonstrate that long-standing local claims regarding the presence in Rome of ancient artifacts from the Jerusalem Temple and their subsequent conservation in the Lateran acquired particular potency in the twelfth century. Jews and Christians participated in a common religious discourse that invested remains from the biblical and Jewish past reportedly housed in Rome with symbolic capital valued by the two communities and that thus fostered both contact and competition between them. During this pivotal century and within the special microcosm of Rome, Jews and Christians experienced unusually robust cultural and social interactions, especially as the Jews increasingly aligned themselves with the protective power of the papacy.