Presidential Metro

The  is a network of metro tunnels that is added to Fallout 3 in the Broken Steel DLC pack.

It connects the Presidential Sub Level beneath the White House with Adams Air Force Base and The Capitol Building's East Wing. Protected and maintained by a computer system called M.A.R.Go.T., the area is guarded by Sentry Bots and swarming with ghouls.

Unmarked quest: Fatal Attraction (Broken Steel)
A holo-tape titled "Sorry, my love" is located up a flight of stairs on a bench near the exit to the capital building east wing. Finding and listening to it will start the unmarked quest Fatal Attraction.

Trivia

 * Near one of the blocked up routes within the line there is a Camera with the flasher being held onto be a Gnome.
 * You can find two Teddy bears tied to the train tracks near the location of the usable train. There will be a "HELP US" sign near the pair.

Appearances
The appears in the Fallout 3 DLC Broken Steel.