Anyone interested in wartime defence structures, shelters, pill boxes and other built relics left behind in Britain from the two world wars, should take a moment to scan this section from the fascinating Derelict London website.
Great shots of command centres, graffitti'd bunkers and underground shelters left to decay in the capital - and a plea for more leads on where to photograph more of these fascinating structures.
http://www.derelictlondon.com/id55.htm