If there were ever a group with the prototypical trappings of a modern fandom, it would be the avid readers of H.P. Lovecraft. For nigh on a century, his works have entranced and transmogrified readers, not unlike the sermons of the Crawling Chaos, the malign Nyarlathotep.
In this already overdone metaphor, the H.P. Lovecraft Archive is a bygone temple, the foundations built aeons ago (1998) and tended by some mad and unseen follower.
While perhaps the most useful area of the site is the complete library of his fiction, it is my no means the only area. The Archive also includes a complete bibliography of his poetry; great scores of his correspondence (he had over 100,000 extant letters); his journalism and literary criticism; and, much more.
As I mentioned in my audiobook review, Lovecraft had many faults, especially what we might call essentialist view of race and eugenics. However, if you’re prepared for that, his works are quite fulfilling as they greatly influenced Horror as a modern genre.