This picture shows an abandoned spur in downtown Washington, DC. It is elevated, but the connection to the main line has been removed, and it looks like the land will be re-developed. This photo was taken from inside the eastbound Amtrak Capitol Limited as it approached the terminal in February, 2002. This elevated track was one of three or four that branched out for a couple hundred feet west from the tracks (according to DeLorme and SPV); both the Pennsylvania and Baltimore and Ohio RRs used this segment of track. The location is just south of Eckington Yard and the Florida Avenue underpass.
Thanks to Mike Palmer for contributing information about this route.