Gothic novels are works of fiction that use elements of horror, the supernatural, and the macabre to create a sense of mystery and suspense. They were popular in the late 1700s and early 1800s, and some of the most famous examples include Horace Walpole's The Castle of Otranto (1764), Ann Radcliffe's The Mysteries of Udolpho (1794), and Mary Shelley's Frankenstein (1818).