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
Central European Highlands altitude (between 400 and 800 m) in which the surplus of annual water balance is less noticeable. It includes the uplands of central and south western Europe. Blocks of elevated highlands are found as dissected plateaus and faulted valleys. These are Messeta plateau of Iberian peninsula, Central massif of France,the highlands of Brittany and south west Ireland, the Rhine highlands, the Vosges, the Black Forest of the Rhine and so on. Central European Highlands The Central European Highlands, in a broad sense, comprise the high mountains of the Alpine Mountains and the Carpathian Mountains systems along with mountainous ranges of