West End of London the Square Mile, is the main business and financial district in London, the West End is the main commercial and entertainment centre of the city. It is the largest central business district in the United Kingdom, comparable to Midtown Manhattan in New York City, Causeway Bay in Hong Kong, Shibuya in Tokyo, or the 8th arrondissement in Paris. It is one of the most expensive locations in the world in which to rent office space. Medieval London comprised two adjacent cities - the City of London (cathedral: St. Paul's) to the east, and the City of Westminster (cathedral: Westminster Abbey)
City of London Bridge, Tower Bridge and the Millennium Bridge. The City's flag flies over Tower Bridge, although neither footing is in the City. The size of the City was constrained by a defensive perimeter wall, known as London Wall, which was built by the Romans in the late 2nd century to protect their strategic port city. However the boundaries of the City of London no longer coincide with the old city wall, as the City expanded its jurisdiction slightly over time. During the medieval era, the City's jurisdiction expanded westwards, crossing the historic western border of the original settlement—the River Fleet—along Fleet