London's equivalent to Wall Street is known as the City of London. This small area in central London, colloquially known as the Square Mile, is London's financial and business center.
The London Stock Exchange is based in the City of London. The insurance company Lloyd's of London is also based there. Additionally, the Bank of England is based in the City of London, and hundreds of banks have offices in the City of London as well.
In addition to serving as London's financial center, the City of London is also the most historic part of London. The City of London represents the original walled city of Londinium established by the Romans around A.D. 50, and archaeological digs have studied a Roman temple of Mithras and an amphitheater there. The City's location on the north bank of the Thames has made it an ideal port for conducting trade and business since the Roman era.