Fort Gorges: accessible only by boat, this centuries-old fort never saw troops or combat.

After the war of 1812, several fortifications were proposed to protect Portland’s harbor.
The largest of these was Fort Gorges, a D-shaped granite fortress, modeled after Fort Sumter in Charleston, South Carolina, and constructed from 1858 to 1864 on Hog Island Ledge in Casco Bay, Maine.
Named for the colonial proprietor of Maine, Sir Ferdinando Gorges, it was constructed to support existing forts, including Fort Preble in South Portland and Fort Scammel built on nearby House Island in 1808. Congress, however, did not fund construction of Fort Gorges until 1857. The walls of the fort were begun the next year, and when the American Civil War broke out in 1861, work quickly advanced.
By the time of its completion, the Civil War-era design was completely obsolete, as its cannon holds were far too small for modern guns. After a failed modernization attempt in the 1870s, the fort sat empty and unused for nearly 100 years. A purpose was found for it briefly during World War II, when submarine mines were stored inside, but after the war, it was again abandoned.

The City of Portland acquired the fort from the federal government in 1960 and transformed it into a public park. The city’s website states the fort is “open for exploring at your own risk.” Despite the fort’s park status, the city in no way maintains it, so it still feels very abandoned and rustic.
Flashlights are necessary to explore the inside of the powder holds, which are very dark even during the day. A stone stairway takes visitors up to the second and third floors of the fort, which have fantastic views of downtown Portland, Portland Harbor, and at least three lighthouses.

The city provides no way to access the park, so you must either take your own boat, kayak, or charter/rent one. It was added to the National Register of Historic Places in 1973.

Images from web – Google Research