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.
It's a members-only library but you might be granted access with a research request. The writer's room is great but there's a few special, hidden corners among the bookshelves to tuck yourself away in.
A winding side street that links hectic Oxford Street and Tottenham Court Road, Hanway Street, with its odd mix of old-style Spanish flamenco bars and second-hand vinyl stores, is a bit of an anomaly. I’ll be surprised if they all withstand the Tottenham Court Road redevelopment but I hope they do.
I love swimming and I love being outside. London is great if your into both these things. I swim at London Fields Lido which is heated all year round. Its best in the winter when the steam rises from the water and if your lucky its snowing a little on your head. If your brave you can also go for the unheated option of the Serpentine or Hampstead Ponds.