Ha Ha Tonka State Park is a public recreation area encompassing over 3,700 acres on the Niangua arm of the Lake of the Ozarks, about five miles south of Camdenton, Missouri, in the United States. The state park's most notable feature is the ruins of Ha Ha Tonka, an early 20th-century stone mansion that was modeled after European castles of the 16th century. The park also features caves, sinkholes, and bluffs overlooking the lake.