The City is the oldest part of London. It is here that the Romans formed a settlement nearly 2000 years ago. Now the City is financial and business centre of London. It contains the Royal Exchange, Bank of England, the Mansion House, the official residence of the Lord Mayor of London, and the headquarters of many of the wealthiest companies and corporations in the world. During the daytime nearly a million people work there, but less then eight thousand people actually live there. The City occupies a mile in the middle of the capital. It once made up the entire town of London, surrounded by the wall. There are still many reminders of its historical past. Saint Mary-le-Bow is famous for its "Bow Bells", which used to ring daily. A true Londoner, a Cockney, has to be born within the sound of the bells. World banks and trading companies have offices in the City. The biggest is the Bank of England, which looks after the accounts of the British Government. It has its own nickname, "the old lady of Threadneedle Street". The monument to commemorate the Fire of London was built in the City. A brass ball covered with brass flames. The tower is 62 metres high and 62 meters away from the baker's shop in Pudding Lane, where the fire began. There are 311 stairs to the top of the monument. It is a great tower!