What lay behind our joint love of shadows and marvels was, no doubt, the ancient, mouldering, and subtly fearsome town in which we live witch-cursed, legend-haunted Arkham, whose huddled, sagging gambrel roofs and crumbling Georgian balustrades brood out the centuries beside the darkly muttering Miskatonic[River].

An excerpt from The Thing on the Doorstep (1933) by HP Lovecraft
first published in Weird Tales 1937

Legend haunted, ghost drenched, lousy with professors and cultists Arkham, MA. A town created by HP lovecraft. Featured in several stories by him and a few other writers. Later becoming the name of the Asylum for the Criminally Insane in the Gotham, first appearing in Batman in issue #258 of the Batman comicbook.

This episode doesn’t have anything to do with Batman.
Infact I won’t even talk about how Arkham appears in TMNT #29 along with giant robots,  zombies, and the Necronomicon.

Etc.

HPLHS
HPLFF
Dreams in the Witch House: A Lovecraftian Rock Opera
The Dunwich Horror (1970)
The Color Out of Space
Masters of Horror: Dreams In The Witch House
The Collect Call of Cathulhu
Danvers Mental Hospital
Arkhams IRL location
A Shoggoth on the Roof