The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a sovereign state in Europe. Lying off the north-western coast of the European mainland, it includes the island of Great Britain (the name of which is also loosely applied to the whole country), the north-eastern part of the island of Ireland and many smaller islands. Northern Ireland is the only part of the UK that shares a land border with another state—the Republic of Ireland. Apart from this land border, the UK is surrounded by the Atlantic Ocean, with the North Sea to its east, the English Channel to its south and the Celtic Sea to its south-southwest. The Irish Sea lies between Great Britain and Ireland. With an area of 93,800 square miles (243,000 km2), the UK is the 80th-largest sovereign state in the world and the 11th-largest in Europe. It is also the 21st-most populous country, with an estimated 64.5 million inhabitants.
London is the capital and most populous city of England and the United Kingdom. Standing on the River Thames in the south east of Great Britain, London has been a major settlement for two millennia. It was founded by the Romans, who named it Londinium. London's ancient core, the City of London, largely retains its 1.12-square-mile (2.9 km2) medieval boundaries and in 2011 had a resident population of 7,375, making it the smallest city in England. Since at least the 19th century, the term London has also referred to the metropolis developed around this core. The bulk of this conurbation forms Greater London, a region of England governed by the Mayor of London and the London Assembly. The conurbation also covers two English counties: the small district of the City of London and the county of Greater London. The latter constitutes the vast majority of London, though historically it was split between Middlesex (a now abolished county), Essex, Surrey, Kent and Hertfordshire.
Bath is a city in the ceremonial county of Somerset, England, known for its Roman-built baths. In 2011, the population was 88,859. Bath is in the valley of the River Avon, 97 miles (156 km) west of London and 11 miles (18 km) south-east of Bristol. The city became a World Heritage Site in 1987.