This is central London – you can see the rest of the city over at Londonist.
Many of the names will be familiar. The Black Freres were settling in nicely in the south-west corner of the City. The small hamlets of Stokewelle, Clopeham, Totinges and Mordune clustered around the old stone road to the south. The adventurous traveller might also sojourn to the extreme north, and visit the villages of Barneto, Myllehill or Cokfosters. But then, too, there are many names that might be unfamiliar. Who now ventures to Tokyngton?
He tells BuzzFeed the most helpful resource was British History Online:
He's been writing about the city for a decade, so had "a head full of useful leads before I started". The idea came from this hand-drawn map he'd made a few years ago. Still, the project took about 20 hours to research and draw.
Now he's working on a detailed map of every location mentioned in every Dickens story ever – "but that'll take a couple more years!"