For an unusual experience while visiting in Downeast Maine, try exploring the historic site of Fort O'Brien. Exploration and picnicking are popular activities at this site. Built first in 1775, the Fort has been totally destroyed at least twice, but was rebuilt and continues to guard the mouth of the Machias River. Over a period of ninety years, Fort O'Brien was changed but it remained active from the time of the American Revolution, to the War of 1812 and finally during the Civil War.

While exploring this earthworks fort, you will notice a bronze cannon that is affectionately referred to as "Napoleon". This unique piece of armory equipment fired twelve-pound cannonballs, canister, or spherical case shot. This cannon tube weighs 1216 pounds and was made at the Ames Manufacturing Company of Chicopee, Massachusetts in 1862. The "Napoleon" was originally mounted on a wooden carriage that weighed 1128 pounds. Just imagine trying to move that piece of equipment! In the best of conditions, this gun could fire a ball 1600 yards – the distance required to reach across the mouth of the Machias River.

Fort O'Brien is definite part of the war history of the Eastern United States.