St Paul's Cathedral, London
A wonderful landmark, currently undergoing a bit of work which limited my angles for photographing when I was there a couple of weeks ago.
Luckily, I had lovely sunshine and blue sky/cloud to help set off the building as a background.
Going inside, they prefer you to not photograph the interior. This is a shame as it has some lovely viewpoints and items of interest that would make thought provoking and arresting images.
If you are brave (and fit enough) a walk to the roof of the dome is a must!