Mars Hill was inspired by a real place near where I live on the coast of Maine, a 100+ year old Spiritualist community called Temple Heights: little carpenter's gothic cottages tumbling down a hillside overlooking the sea, very picturesque and, tragically, very susceptible to the terrible development pressure that's bearing down on the small towns around here.
So far, however, the spiritualists seem to be winning out. After I wrote "Last Summer at Mars Hill", I visited the place formally and had a reading done by a psychic there. The place was exactly as I'd imagined it, as were its (human) inhabitants. I saw no evidence of supernatural ones, alas.

Apocalypse Descending (2002)