The United Kingdom is a group of islands off the west coast of Europe, which comprise the countries of England, Wales, Scotland and Northern Ireland. London is the overall capital and biggest city, although each separate country has its own capital: Cardiff for Wales, Edinburgh for Scotland and Belfast for Northern Ireland. Organising a hire car in the United Kingdom is the best way to enjoy these different countries. As well as the lure of the capitals, the UK's highlights include England's royal palaces and lively cities, the Welsh castles, Northern Ireland's Giants Causeway and Scotland's mountainous landscapes.