The United Kingdom, also known as Great Britain, is a sovereign state that is made up of four constituent countries: England, Scotland, Wales, and Northern Ireland. It is located in northwest Europe and borders the Atlantic Ocean to the west and the North Sea to the north. The UK is a parliamentary democracy and a constitutional monarchy. The capital city is London, which is a global financial and cultural center. The UK is known for its rich history, cultural heritage, and diverse landscape, which includes rolling hills, mountains, and coastlines. The country is also home to many world-renowned universities and research institutions, and is a leading player in global politics, economics, and culture.