$8; free (ages 0-3 and active military with ID). Cash or check only for tickets purchased at gate; debit cards include $2 fee.
Guided 45-minute tours are given daily every 12 minutes Mon.-Fri. 10-6, Sat.-Sun. 9-7, Memorial Day-Labor Day; every 15 minutes Mon.-Fri. 10-4, Sat.-Sun. 10-5, rest of year. Last tour begins at closing. Advance ticket purchase is recommended in summer.