The Royal Park offers great views of London and the city; As well as housing the Royal Observatory which includes a museum of astronomical and navigational tools, part of the National Maritime Museum.
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.
Morito is a few doors down from it's well know sister restaurant Moro. This not long open tapas restaurant feels like it could be in a little back street in Barcelona. The food is great, and it has a buzzy but relaxed atmosphere. You might need to wait a little while for the table, but I promise it's worth it.