This article explores the ongoing fascination with Foucault's brief and rather sketchy idea of heterotopia. Drawing out some key lessons from the most sustained interpretations of this curious spatio-temporal concept, it addresses weaknesses and potential contradictions and goes on to highlight trends and emerging themes in studies that incorporate the notion. The article argues that although the uses of Foucault's accounts of heterotopia are bewilderingly diverse, heterotopias are most productively understood in the context of Foucault's insistence on ‘making difference’ and their adoption as a tool of analysis to illuminate the multifaceted features of cultural and social spaces and to invent new ones.