True but then you and I know London and you can walk from one side to the other in a couple of hours same as Paris.
People get confused as to what constitutes London. As far as I am concerned, in this context, it extends only from the Thames to the Marylebone Road and from Marble Arch to the River Lee (just past the Blackwall Tunnel approach). Nothing much outside of that counts ~ I am prepared to cross the river but only to get to the South Bank or Waterloo.