The highest point reached by London Underground trains is at Amersham on the Metropolitan Line at about 500 feet above sea level. However the highest point above the ground is reached on the Dollis Brook Viaduct on the Mill Hill East branch of the Northern Line which is 60 feet above the road below.
The lowest point on the system is just south of Waterloo station on the Northern, where the tracks are 70 feet below sea level. The absolute deepest part of the system is also on the Northern where, below Hampstead Heath, the rails are over 220 feet below the ground.
Nearby Hampstead station is also the deepest station on the network at 192 feet below ground level. The platforms here are reached by the deepest lifts on the system which descend 181 feet."
Re: London Underground highs and lows
The highest point reached by London Underground trains is at Amersham on the Metropolitan Line at about 500 feet above sea level. However the highest point above the ground is reached on the Dollis Brook Viaduct on the Mill Hill East branch of the Northern Line which is 60 feet above the road below.
The lowest point on the system is just south of Waterloo station on the Northern, where the tracks are 70 feet below sea level. The absolute deepest part of the system is also on the Northern where, below Hampstead Heath, the rails are over 220 feet below the ground.
Nearby Hampstead station is also the deepest station on the network at 192 feet below ground level. The platforms here are reached by the deepest lifts on the system which descend 181 feet."
From: http://www.londonrailways.net/html/information.html