Real Harry Potter inspiration alert: I walked past this sign every day on my way to work when I was living in Clapham .
J.K. Rowling used to walk past a street sign while living in Clapham back when she was still setting up the Harry Potter universe in her mind.
S.W.11′, is what prompted Rowling to name the potions master Severus Snape.
With the upcoming Fantastic Beasts movie, Rowling is preparing to tie the world of the franchise even more closely in with Harry Potter, with a deeper exploration of Dumbledore and Grindlewald’s backstory.