"The Castle of Otranto" is a novel written by Horace Walpole and first published in 1764. It is considered the first Gothic novel, setting the stage for a genre that would become popular in the late 18th and early 19th centuries. The book is known for its blend of supernatural elements, romance, and suspense. The story is set in the medieval Castle of Otranto in Italy and revolves around the mysterious and supernatural events that unfold within its walls. The narrative involves a cursed noble family, secret passages, prophecies, and a large helmet that seems to portend doom. The novel explores themes of power, love, and the supernatural, creating an atmospheric and suspenseful tale.