Starkesboro is a fictional town in the Marvel universe which first appeared in 1972 in issue #4 of the 1st volume of the Marvel Premiere comic series. It's a pastiche of the Innsmouth of canon.
15,000 years ago, the body and soul of Slorioth, one of the Old Ones, were bound to the land by a cabal of ancient sorcerers. Land which millennia later would be known as New England. At some point in time, N'Gabthoth another Old One, established himself in a nearby cavern in the ocean, where he slept.
Centuries ago, in what would become the state of Maine, a village was founded by fisherfolk. Over time the village would become the town of Starkesboro. Later, a serpent-twined inverted cross was found floating in the sea. It was brought into town, which resulted in Sligguth's power infiltrating the population. Sligguth an agent of Shuma-Gorath, the ruler of the Old Ones, permitted one of its residents (Ebora) to remain completely human, and mutated the rest into semi-reptilian subhumans. Ebora a magic user, became his high priestess. They desecrated the local church and performed various rituals to Sligguth, including human sacrifice.
Sligguth took up residence below the church in a cavern, and would come up to the surface to get his human sacrifice. It was a town with a dark magical aura which Dr. Strange was barely able to overcome while in astral form. Those who left were pulled back to the town by Sligguth's influence and the chants of its locals awakened their inner Serpent-Men. Upon the defeat of Sligguth and later N'Gabthoth whom they worshipped by Dr. Strange, they fled into the dark hills.
Two decades later it's new inhabitants were turned into werewolves by the criminal scientist Nightshade (whom was allied with the cult leader Dredmund Druid). They were stopped by Captain America and his allies, who forced them to cure the residents. A few years later, the superhero and ex-Avenger Doctor Druid was manipulated and corrupted by Slorioth into releasing him from his imprisonment. Slorioth burst from the land and battled both the Defenders and Secret Defenders whom were failing in their attempt to contain him much less defeat him. The godlike trio, the Vishanti, intervened and summoned the multiversal entity, Living Tribunal. Who judged Slorioth a threat to the reality, and banished him.