Washington, D.C.

Based on concept art released on the Fallout 3 teaser page, Washington, DC, the pre-War capital city of the United States, will be one of the major locations in the game. One of the images shows the (largely intact) Capitol, while another shows the Jefferson Memorial converted to a water filtering facility.

It should be noted, however, that those two images by Craig Mullins are early concept art and do not necessarily reflect the actual game.