We focus on the European Quarter in Brussels as a political place and the spatial context of European Union (EU) policy making. In addition to the EU institutions, the political place consists of a political agglomeration of various kinds of actors, from EU bureaucrats and politicians to a variety of stakeholders and lobbyists from all over the EU, who are permanently present in the Brussels neighbourhood. We present, firstly, the EU Quarter as a fixed setting for policy making with a relatively constant physical, locational and functional shape, and a specific sense of place as the EU bubble. Secondly, we emphasise the fragmentation and fluidity that portray it as a place divided into various political assemblages that make the place an assemblage of assemblages consisting of smaller and constantly evolving sub-processes. Thirdly, we aim to demonstrate the mobile and geographically distributed nature of EU policy making, and thus the dispersal of the political places where it takes place. This generates mobility of different kinds, which include not only the circulation of political ideas and people between different sites of the EU political system, but also the monthly migration of the Parliament and related lobbyists to Strasbourg. We believe that these three aspects of political place help the understanding of the situated but simultaneously spatially dispersed and mobile nature of EU policy making, and the study of the political places in other urban contexts.