Whenever I work in the city library in Cambridge I often find my gaze drifting out across the view of rooftops - it's a real jumble of old and new. This is one little section - the back of the Guildhall, I think. It's surprising how many people you see come out onto the roof of various buildings - usually for a fag break!
I love a nice rooftop shot - I hope all these roofs are fireproof!! Adam insists there is public access to the top of the Guildhall - it would be a good vantage point for a photo but I haven't been brave enough to try....