$22; $20 (ages 13-17, ages 60+ and college students with ID); $10 (ages 7-12).
Tours depart daily on the hour 9-7 (also on the half-hour, June-Aug.), Apr.-Sept.; 10-6, rest of year. Tickets are available online or on a first-come, first-served basis; arrive early. Closed Thanksgiving and Christmas. Allow 1 hour, 30 minutes minimum.