Keith Fawkes, NW3 1HJ
A bookseller on Flask Walk just behind Hampstead Station.
This place is one of those quintessential ramshackle shops, poky and dark as every available space is filled floor to ceiling with shelves threatening to crumble under the weight of all the collected tomes. More newly acquired books are in piles on the floor wherever there's a space, and there's some particularly large piles of art books. The many piles and very cramped spaces make it difficult to sometimes see what's available.
Most genres are covered and the shopkeeper was happy to help me find the London section, which covered about three shelves.
This is the kind of place you can find some great stuff in, but you'll need most of an afternoon to do so.
Accessibility: Steps down to get in, and very very little space is available between the bookshelves.
Comment added by Marky: This is a gem of a bookshop and how antique bookshops should be - although it would be nice for it to have more space and be able to see the books without a rummage, but this in a way is part of its charm. You never know what book you might find there. The staff are helpful - particularly the American gentleman and outside there is at weekends and certain times a wonderful stall that sells miscellaneous antique items.
There are not many places like this around anymore and I hope that it lasts forever.