The paper considers Leros in the Greek Dodecanese as a case study in the history of rationalist architecture of the fascist Italian regime, implicating varied forms of surveillance, exile, detainment, and incarceration. The paper explores the enduring legacy and impact the colonial and military architecture, policy, and planning have had on urban and architectural forms, local labour economies, and the community that continues to the present day. The research spans from the Italian occupation of Leros to the establishment of detention centres for refugees today, following the chronologically overlapping trans-institutional transformation of Italian military and medical infrastructures into notorious mental health care facilities and camps for political prisoners and violently displaced children from mainland Greece. The paper focuses on the relationships established by the plan, the architecture, the strict imposition of gerarchia [hierarchy], as defined elsewhere by Diane Ghirardo, and associated governing frameworks, which established a unique urban form and social fabric. The paper explores not only the aesthetic and formal qualities of the architectural object but also the socio-political diagram embedded in the logic of the ambitious building programme of the Italian occupation. It will further examine the spatial tactics and policies that supported Italian control and, consequently, the gradual erosion of agrarian traditions and capabilities of the local population, forcing them into a complex co-dependence. It is precisely the interdependence and co-existence of architecture and labour that perpetuates the island’s role as an apparatus of control, creating a carceral campus of surveillance and exile.