As a part of the “Nat Geo Adventure” series, National Geographic has a Lovecraftian travel guide to New England.
The guide is well thought out and includes visits to Innsmouth, Kingsport, and Arkham, or rather their real life inspirations. It also details certain locations in Newburyport (Innsmouth), Marblehead (Kingsport), and Salem (Arkham) that were used in Lovecraft’s writings.
I’ve seen other such guides that aren’t as complete. There are a few published guides as well, but for a freebie this is pretty good. If you’re planning a trip to New England, say for Pax East, you might want to make a day out of visiting the dark realms of Lovecraft’s stories.