The Groton Monument, sometimes called the Fort Griswold Monument, is a granite monument in Groton, Connecticut. It is dedicated to the defenders who fell during the Battle of Groton Heights on September 6, 1781. The monument was originally 127 feet (39 m) high, but it was later changed in 1881 to commemorate the centennial of the Battle of Groton Heights; the cupola was removed and replaced by an iron-capped pyramid in emulation of the Bunker Hill Monument. The monument bears a plaque describing the events of the Battle of Groton Heights and another plaque with the names of the Americans who died in the battle. In 1918, lightning destroyed the capstone and damaged the adjacent Monument House Museum which features exhibits about the Revolutionary War. Visitors can climb the monument and visit the museum from Memorial Day through Labor Day.