The Čachtice Castle (Čachtický hrad) is a castle ruin in western Slovakia, next to the village of Čachtice. The castle was built in the mid-13th century. The castle was a residence Elizabeth Báthory who is alleged to have been the world's most prolific female serial killer. In 1708 the castle was captured and plundered by the rebels of Ferenc II Rákóczi. It has been in decay since.