Institutional seats of the European Union are based in Luxembourg City along with the European Investment Bank. The Economic and Social Committee and the Committee of the Regions are entirely based in Brussels while the European Central Bank is based in Frankfurt and Europol is the only agency to have its seat fixed by the treaties, in The Hague. Separately, the Treaty of Nice establishes Brussels as the venue for all formal summits of the European Council after 2004. However some extraordinary sessions are sometimes held outside the city. The European Council's seat is however fixed by a declaration rather than a protocol, meaning it is
Council of the European Union 2017, both the Council of the European Union and the European Council adopted the purpose built Europa building as their official headquarters, although they continue to utilise the facilities afforded by the adjacent Justus Lipsius building. The focal point of the new building, the distinctive multi-storey "lantern" shaped structure in which the main meeting room is located, is utilised in both EU institutions' new official logos. Council of the European Union The Council of the European Union, referred to in the treaties and other official documents simply as the Council is the third of the seven Institutions of the European