[b]Answer:[/b]
This is West Ham station, looking at the concourse through the arch at the bottom of the stairs to the c2c platforms. The unmodified picture is below:

[url=http://www.sucs.org/~cmckenna/photos/quizes/tq2/March/Mar17unmodified.jpg][img]http://www.sucs.org/~cmckenna/photos/quizes/tq2/March/Mar17unmodifiedsm.jpg[/url]
(click for a larger version)