There are stations, tunnels, entire networks of metro train systems worldwide that have been forgotten, lost beneath the streets. These are some sites that catalogue a few of them.
London
- Underground History This is the definitive site- if you only want to have a brief read, choose this one first.
- Brookwood Cemetery Railway The abandoned train of the dead (not a tube I know, but work with me here)
- London railway Branch Lines
- London's Abandoned Tube Stations
Paris
- Métro Closed [English]
- Le métro Parisien [French]
- Closed stations in the Paris subway system [French & English]
New York
Moscow
- Moscow secret subway system A secret tube system built under Moscow from the Presidential Bunker away from the city.
Northern Heights
A plan to extend the Northern line that was almost finished but then abandoned.
- Higate Station
- Northern Heights
- The Northern Heights Line
- OVERGROUND - Northern Heights - April 1970
Other
These are not abandoned and have no real connection here except that they are about the tube and I wanted to link to them somehow.
- tubeguru A guide to pub/club/bars and venues located near stations. Handy if you're meeting someone.
- London Tube Map with Walklines - sometimes it's quicker to walk It's the connection times between stations that takes the time. This map shows links between any stations that are closer than 500m.