Castle Williams is a circular defensive work of red sandstone on the west point of Governors Island in New York Harbor. It was designed and erected between 1807 and 1811, designed by the Chief Engineer of the US Army Corps of Engineers, Lt. Col. Jonathan Williams, for whom the fort is named, and considered a prototype for new forms of coastal fortification. The castle was one component of a larger defensive system for the inner harbor. Now a under the care of the National Park Services, Castle Williams is open to the public until October 31st.
Going Around Castle William - Guided Tours at 11:30 AM, 1:30 PM and 3:30 daily. About 30 minutes. Get some history in the round at the best-preserved circular fortification in the nation. Special access to 2nd and 3rd floor casemates and rooftop (Rodman gun, view of NYC). Must be able to climb 3 flights of steps.
Self-Guided Tours- Open 10AM-4:30 on weekdays, 10AM-5PM on weekends. A promenade (view of NYC), 1st floor casemates, our passport stamp, junior ranger program, and exhibits.
More information at http://www.nps.gov/gois/index.htm