"The Dunwich Horror" is a short story by H. P. Lovecraft. Written in 1928, it was first published in the April 1929 issue of Weird Tales (pp. 481–508). It takes place in Dunwich, a fictional town in Massachusetts. It is considered one of the core stories of the Cthulhu Mythos.
This is the 1940s radio dramatisation of the story, from the series Suspense, starring Ronald Colman as Henry Armitage