London is the capital and largest city of England and the United Kingdom. The city stands on the River Thames in the south-east of England, at the head of its 50-mile (80 km) estuary leading to the North Sea. The City of London, London's ancient core and financial centre − an area of just 1.12 square miles (2.9 km2) and colloquially known as the Square Mile − retains boundaries that closely follow its medieval limits.

New York City (NYC), often called simply New York, is the most populous city in the United States. It is located at the southern tip of the U.S. state of New York. New York City is composed of five boroughs, each of which is a county of the State of New York. The five boroughs - Brooklyn, Queens, Manhattan, the Bronx, and Staten Island - were consolidated into a single city in 1898.