This may not be much of a secret but deserves a mention. I find it hard to go anywhere near this place without having to go there. Freshly baked Beigels hot salt beef and it never closes, 24 hours a day 7 days a week.
I grew up around this area - it really is a gem of a place. The interior is so cool, with sort of organised clutter everywhere. They have a little garden and they serve food. Its not the best in the world, but the whole experience there is great.
Probably my favourite building in the city, and right in the heart of it. There are always interesting events happening here, across art and music, and you can drink in the courtyard during summer
It is one of the most important business centres in London. Crowded of suits at daytime, perfectly deserted at night. It is so striking relaxing to walk in there enjoying the silence and the lights! It makes you feel pleasantly far from reality.