London is the capital and largest city of England, and the United Kingdom, with a population of around 8.8 million, and the largest city in Western Europe by metropolitan area, with a population of 14.8 million.

Paris is the capital and most populous city of France. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, culture, fashion, and gastronomy. For its leading role in the arts and sciences, as well as its early and extensive system of street lighting, in the 19th century, it became known as the City of Light.

Rome is the capital city of Italy. Rome is located in the central-western portion of the Italian Peninsula, within Lazio, along the shores of the Tiber. Vatican City (the smallest country in the world) is an independent country inside the city boundaries of Rome, the only existing example of a country within a city.

Venice is a city in northeastern Italy and the capital of the Veneto region. It is built on a group of 126 islands that are separated by expanses of open water and by canals; portions of the city are linked by 472 bridges. The islands are in the shallow Venetian Lagoon, an enclosed bay lying between the mouths of the Po and the Piave rivers.