Hardenburg castle, built in the 13th century, was the ostentatious residence of the Dukes of Leiningen and is one of the biggest castle ruins in the country. With its many towers, stairs and passages it invites young and old visitors to discover, experience and conquer. The visitors centre offers an exhibition, film and multimedia guides. Guided tours on demand. Phone: 06322-935140. Jan-Mar and Oct-Nov 9-16:30; Apr-Sept 9-18 o’clock. Closed in Dec. and on every first working day of the week.