Hours: Fifty-minute guided tours are given every half-hour Mon.-Fri. 10-4:30, Sat. 10-6, Sun. 10-5, early June-Labor Day; on the hour Mon.-Fri. 10-3, Sat.-Sun. 10-4, late May-early June and day after Labor Day-early Oct. (weather and conditions permitting). Ages 0-12 are not permitted on tours at 10, 12:30 and 3:30, early June-Labor Day. Other tours are offered; phone for schedule and prices.