Not the most exciting place inside, but a lovely rooftop area which not all that many people seem to know about, 2 mins walk from Old St station. If it’s packed then The Red Lion is just up the road.
I personally love photo arts and this gallery puts on some amazing exhibitions by the best artists, such as Vivane Sassen and Gregory Crewdson. The Gallerys’ six-storey space is located right by Oxford Street, so if you are doing some shopping in London, you might as well stop by this gallery. The upper floors consist of two new galleries, while the ground floor hosts a nice café/restaurant. Together with the print sales, the bookstore occupies the basement of the building. I can spend hours just looking at the books, how it is designed, bound, as well as the prints for sale. You can buy all kinds of film; medium format to polaroid film at the store. After some hours at this gallery you just want to go home and start making some photography!
A great walk down an old abandoned rail way from Finsbury Park to Highgate. Most of the original platforms are sill remaining so its an interesting place to explore...