Two parallel developments in the Hellenistic period concern urban religious form. One is the increasing tendency towards inter-urban, mondial festivals, with catchment areas at multiple scales ranging from the local region to across the Mediterranean. The other is the increasing tendency towards inward-facing sacred architecture, particularly peristyle sanctuaries, but also theatres and stadia. Until now these have been examined as separate developments emerging from either new institutional practices or new architectural conceptualizations of public and private space. I suggest instead that these were not only related developments, but stem from a third tendency in the Hellenistic era, that of cities to connect. The major festivals were resoundingly inclusive events, with regional and transregional theoric initiatives that could include local marginalized groups as well. The enclosure of this festival space may show similarities with other spaces within the urban topography that were exclusive per definition, but this is due to the logic of design in fostering social cohesion. Ritual profoundly amplifies the effect. The concentration of space and attention facilitates the common knowledge and collective emotional energy needed to create a transformative and transregional experience. These ‘sacred circles’ served as powerful repeaters of this festival network, transmitting a dynamic flow of ideas that spilled over into other areas. Cities began to resemble each other more and more as this cosmopolitan culture took hold across the Mediterranean and well beyond.