FORT GEORGE, Castine. Built by the British in 1779, it was occupied by them until the end of the Revolutionary War. State owned. Parts of Fort George have recently been excavated.

FORT KNOX, Prospect. Begun in 1844 to offer protection to the Penobscot River region just following the northeast boundary dispute. It is the only Maine fort with some of its original cannon emplaced State owned; fee.

FORT MADISON, Castine. Built in 1811, it was renamed Fort Castine while occupied by the British in 1814 and 1815. Earthworks remain. Town owned.

FORT O'BRIEN, Machiasport. Dating from 1775, it overlooks Machias Bay, the site of the first naval battle of the Revolutionary War. State owned.

FORT POWNALL, Stockton Springs. Dates from 1759. Earthworks remain, excavation of some foundations. Fee.

FORT SULLIVAN, Eastport. Dates from 1808-9. The barracks still remain, thought hey were moved after the Civil War. Part of the brick magazine remains on the original site. Owned by the Border Historical Society; fee.