It is a diagram style map - made to be easy to read and not for geographical accuracy.
On the London Underground map, the Circle Line is coloured yellow.
London England 1863
The Underground, more commonly called the Tube.
about 789234
Hammersmith and City
The modern London Underground schematic map was designed by Harry Beck in 1933.
In Harry Potter and the Sorceror's Stone, Dumbledore claims to have a scar above his left knee that is a perfect map of the London Underground.
Get a London Underground map and count them yourself!!
On the London Underground map, the Circle Line is coloured yellow.
It is a perfect map of the London Underground. Of course, that was in 1981 and the underground changes.
According to his wikipedia article he is best known for his creation of the London underground (subway) map.
It is stored in his brain
Created in 1931 Harry Beck invented the iconic London Underground (tube) map in 1931 - not the underground railway.
Henry Charles Beck (Harry Beck), invented the iconic, topological London Underground map in 1931 while working as a draughtsman for London Underground. It was a spare time project and not part of his job description.
Y The Piccadilly Line
Dumbledore had the scar. It was a perfect map of the London Underground.
Henry Beck (AKA Harry Beck) introduced the present London Underground Tube map in 1931. More information on Harry Beck is available here: http://en.wikipedia.org/wiki/Harry_Beck