In modern times many cities have grown bigger and bigger. The whole area is often called a " "metropolis" " and can sometimes include several small ancient towns and villages. The "metropolis" of London includes London, Westminster, and many old villages such as Notting Hill, Southwark, Richmond, Greenwich, etc. The part that is officially known as the " City of London " only takes up one square mile. The rest is known as "Greater London. " Many other cities have grown in the same way.