What is cthulu mansion?

Cthulhu Mansion is a fictional concept created by H.P. Lovecraft in his horror stories. It is depicted as a sprawling, eerie and ancient mansion located in the town of Arkham, Massachusetts, which is made uninhabitable by the presence of dark forces. The mansion is believed to be haunted by the interdimensional creature Cthulhu, a powerful and evil being worshipped by a cult of devoted followers. It's a central location in many Lovecraftian stories and its lore has been adapted by numerous writers, filmmakers, and game designers in various forms of media.