Rick Edmondson's Unfinished Buildings

Derelict London, a fabulous collection of photos of, well, derelict London

War-time pill boxes, a reminder of when Britain stood alone against Nazi Germany

Silent UK - urban exploration, these good folks pass their time by opening up manholes, going down - the main sewers in larger towns are big enough to walk along - and having a good explore. Apart from probably not being able to go home on the bus afterwards, it sounds really interesting. Hmmm.