Harbor Islands- Long Island in Boston in Suffolk County, Massachusetts — The American Northeast (New England)
Coastal Mines
Fort Warren-Georges Island
| | Boston Harbor Islands National Recreation Area | |
Inscription.
Harbor mines and cables fill the pier during the Second World War. Built in 1906, the mine-storage building (background) now houses the visitors center. (Inscription below the title) Countering the threat of the submarine, the U.S. military mined the nations ports---conventional artillery, like Fort Warrens 15-inch guns, couldnt destroy underwater invaders. Beginning in 1898, the Coast Artillery placed minefields in maritime channels north and south of Georges Island (some minefields were further north, near Lynn). To avoid damaging friendly ships, soldiers in casemates (bunkers) controlled the mines via underwater cables. The cables were checked for short-circuits in water-filled concrete tanks (now below the food-service area) before being transported with the mines on railway cars to the docks.
Topics. This historical marker is listed in these topic lists: Forts and Castles • Military. A significant historical year for this entry is 1906.
Location. 42° 19.188′ N, 70° 55.8′ W. Marker is in Boston, Massachusetts, in Suffolk County. It is on Harbor Islands- Long Island. It is on Georges Island. Island is only accessible by boat. Touch for map. Marker is in this post office area: Hull MA 02045, United States of America. Touch for directions.
Regionally, this marker is in Historic Boston and on the South Shore. It is also in the American Northeast, in New England, and on the Eastern Seaboard. Globally, it is in the North Atlantic Region, North America, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it finds itself in what was once one of the original Thirteen Colonies.
Other nearby markers. At least 8 other markers are within walking distance of this marker: Confederate POWs (within shouting distance of this marker); Defense System (about 400 feet away, measured in a direct line); Escape! (about 500 feet away); Fort Warren (about 500 feet away); Powder Magazine (about 600 feet away); Parade Ground (about 800 feet away); Bakery (approx. 0.2 miles away); Political Prisoners (approx. 0.2 miles away). Touch for a list and map of all markers in Boston.

Photographed by Don Morfe, October 3, 2010
3. Coastal Mines Marker
Welcome to Fort Warren-It was built more than 150 years ago-a fort on an island, a key to the coastal defense of a new nation.
It was transformed into a prison during the Civil War, housing hundreds of Confederates within its granite walls, ordinary soldiers and high level politicians alike. It served our nation for more than 85 year as a vigilant sentinel in the harbor. It made over into a park is an extraordinary island setting. Welcome to Fort Warren, on Georges Island. Welcome to the Boston Harbor Islands National Recreation Area.
Credits. This page was last revised on January 30, 2023. It was originally submitted on January 12, 2013, by Don Morfe of Baltimore, Maryland. This page has been viewed 590 times since then and 17 times this year. Photos: 1, 2, 3, 4. submitted on January 12, 2013, by Don Morfe of Baltimore, Maryland. • Bill Pfingsten was the editor who published this page.


