Founded in the late fourth century BCE as a Seleucid military outpost on a local stronghold known to locals as Dura, ‘the fortress', Europos in Parapotamia turned into a full-fledged, grid-planned settlement in the second century BCE under the last decades of Seleucid control on the region. It then flourished under the Parthians, before its conquest by the Romans in the mid-second century CE and its subsequent transformation under a military camp then besieged and conquered by the Sassanid armies in the mid-third century. The site was then abandoned until its rediscovery in 1920 and excavations, first by a joint expedition from Yale University and the French Academy (1929-1937), and then by French-Syrian expedition (1988-2011). Although most of the discoveries relate more directly to the last century of occupation in the site, the thorough excavations have also yielded many traces of the previous Seleucid and Parthian periods, when this middle-size settlement along the Euphrates River served as the administrative centre of the Parapotamia district. In this paper, we will more particularly focus on the place and evolution of the open, public spaces. While the original excavation reports have mostly concerned the architectural remains and finds (coins, pottery), treated in separate volumes, we propose to look at these spaces in a wider perspective encompassing the variety of the evidence uncovered in Dura/Europos and in the light of the wider, regional context. The primary focus of this presentation will be the central square of the agora of the city, which was extensively uncovered in 1931-1936, and where the author led new fieldwork in 2005-2010, around the archival office, the Roman market, and the earliest levels of occupation. It will be completed by some preliminary observations on the streets and other open esplanades within the city walls. By looking at the access to the public spaces, the activities they accommodated, and the people frequenting them, as evidenced by archaeological finds and textual testimonies, we thus aim at uncovering social practices associated with these public spaces and their evolution in the Seleucid, Parthian and Roman times.