Stairs of some buildings of the medieval Jewish worship Montpellier. The bone of Barralerie in Montpellier, whose facades are completely remodeled in the eighteenth century, preserved in a set back Jewish worship mentioned by the great local historians. Prior to its classification in the category of historical monuments in 2004, made an assessment on the potential archaeological medieval preserved mainly in the hotel Auteract notary, acquired by the council. If Montpellier is presented in the tenth century as a fortified single primitive nucleus, was strong in the context of urban renewal in the early thirteenth century when the Jewish community settled. The neighborhood is chosen from the pool of two blocks separated by an alley primitive but following a large shaft that connected the stately palace to the city markets. They are distinguished on the lane line of the synagogue building, the mikveh and the house of charity. In efervesciencia of the early thirteenth century, the old plot consists of small units underwent numerous transformations to build larger spaces in the form of patrician houses. This applies to the synagogue, which has a façade of more than 10 m long. This situation led to certain restrictions and adaptations. The plant peculiar to the synagogue evokes the probable existence of two previous homes, and the disparity of the building which houses the synagogue and mikveh indicates that it is previously dividing two houses: this is confirmed by the orientation of the plot, the junction of the two facades, the unevenness of the floors and roofs, and the absence of direct communication between the two sites. However several common elements testify to the transformation into a community together: the alignment of the three doors of the synagogue, mikveh room floor and facing the alley in the basement excavation for the pool mikveh ritual and the lower hall in the basement of the synagogue with the ground at the same level, same height of the vault vaulting technique and the same for both spaces. The building which houses the mikveh is only kept to the first floor. The upper part was rebuilt in the sixteenth century, but in the basement is a room up to the dead whose function is still unknown, a narrow staircase leading to the locker room with niches and benches as well as the swimming pool carved more than 6 m below the street. The synagogue building has for its part a comprehensive and consistent medieval elevation, consisting of a large low room in the basement, two floors and attic. The lower room communicates directly with the synagogue by a staircase and an opening in the dome (Figure 3). Alley a pointed door opens to the space of a single stretch cultic perhaps holding a platform as suggested by two arcs preserved corners (Figure 4). This peculiar structure requires the integration of a distribution system, covering and lighting that suits a piece that rises from one stretch to the first floor, or about 8 m high, which is confirmed by the absence of holes for the decking and the existence of a large paired vain at ground level. The rise of the Jewish community to his first exile in 1306 resulting in topographic location of the synagogue as mandated by the rule in the upper part of the city near a water source, in this case the water table and in the presence of units of a religious nature to the mikveh, ritual bath of purification, the charitable nature of the alms house and school didactic nature. The study of this hotel that will shortly be carefully will allow us to further our understanding of medieval plot of the domestic architecture of Montpellier and especially the mode of settlement, the history and customs of the Jewish community thanks to the exceptional preservation of this set of medieval worship.