There are many quirky book stores in London, but I really love the selection that Daunt Books have, they often have bespoke editions which you won't find in other book stores. Also, the people that work there are so helpful and knowledgable. I can never stop myself from walking in!
They mainly sell art and cultural theory books but they also have a good selection of small press and self-published zines. It’s a great place to browse and get ideas.
Also the Queens back garden, these beautiful grounds are great for a Sunday stroll to see the pelicans or to feed the squirrels. Duck Island Cottage is worth a look too, a idyllic little cottage situated in the grounds which was specially built as the bird keepers home.