London Underground, a work of art

150 years ago in 1863 the first train left London. Now the underground system has more trains than ever and takes around a billion people to their desired destinations. Although it does suffer from the occasional hold up, overcrowded carriages and high temperatures the underground has survived many things including the Blitz in World War II and more recently the London 2012 Olympics. Lets take a look at how the tube map has changed.