Crystal City

Crystal City is a district of Washington, D.C. in the Capital Wasteland Cut from the final version of the game, its only remains are the signposts of the Crystal City Metro station(s).

Appearances
Crystal City was going to appear in Fallout 3 but was cut from the final version of the game.

Behind the scenes
In real life, Crystal City is located directly and shortly south of the Pentagon, easily seen on a map. It is highly plausible that Crystal City was an early version of the Mason District, since the Mason District - at least as portrayed in the game - does not exist in real life. Furthermore, the Mason District is in roughly the same location in which Crystal City would be.