It's the sort of thing that turns up in quizzes and that I get asked a lot ... how much of the London Underground is actually underground? Turns out, there's not a straightforward answer as it depends on how you define a station as being 'Underground' ... let's discuss!
Geoff's Actual Underground Map: [ Ссылка ]
TfL's Tube Map Showing Tunnels: [ Ссылка ]
The Section 12 Fire Regulations Map: [ Ссылка ]
