Daily 9-5, Apr.-Nov.; daily 9-4, mid-Mar. through Mar. 31; Fri.-Sun. 9-4, rest of year. Tours depart every 30 minutes daily 9-4:30, May-Sept.; every hour daily 9-4, in Apr. and Oct.-Nov.; every hour daily 9-3, mid- to late Mar.; every hour Fri.-Sun. 9-3, rest of year. Allow 1 hour minimum.