Founded in 1828 the museum houses around 67,000 specimens many of which are now extinct or endangered. My favorite is the skull of a Bottlenose Whale from 1860.
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!