This article focuses on the project for the renovation of a Panopticon prison in Arnhem, the Netherlands (1979–1980), designed by Rem Koolhaas/OMA. The analysis of its reception shows that, despite being well known, it has been little studied and discussed, and although it was not built, it had an impact on prison architecture. It seems appropriate to tackle it now because the Koepelgevangenis (dome prison) of Arnhem has gained current relevance due to plans for it to be turned into a hotel. The renovation project for the Koepelgevangenis explicitly shows the presence of Foucault’s ideas on power and how these ideas exerted significant influence on the works carried out by Koolhaas. For Foucault, the Panopticon prison, such as the Koepelgevangenis, was the paradigmatic example of what he called the “disciplinary society”. Domesticity “behind bars” suggests that prisons can also be understood as domestic spaces. Moreover, it could be said that for Koolhaas, this Panopticon prison was a social condenser or a hotel for voluntary or involuntary prisoners. As a prison or as a hotel, it can also be interpreted as Foucault’s heterotopia, the intervention thus acquiring a new meaning which anticipated the future of this unique building.