Monument and tours free. Tours are limited to 40 people on a first-come, first-served basis and tickets are required for weekday tours. Round trip ferry fare $2; $1 (ages 65+); free (ages 0-12).
Mon.-Fri. 10-6, Sat.-Sun. 10-7, May-Oct. Ranger tours are offered daily. Castle Williams is open Mon.-Fri. 10-4:30, Sat.-Sun. 10-5. Guided tours of Castle Williams' three levels depart at 12:30 and 2:30. Phone ahead to confirm ferry and tour schedules as they may vary.