On the nearby island of New Castle, Fort Constitution was built in 1631 and then rebuilt in 1666 as Fort William and Mary, a British stronghold overlooking Portsmouth Harbor. The fort earned its fame in 1774, when patriots raided it in one of Revolutionary America's first overtly defiant acts against King George III. The rebels later used the captured munitions against the British at the Battle of Bunker Hill. Great view of Portsmouth Lighthouse, next door. Park at the
Battery Farnsworth and walk into the Coast Guard installation to the fort.