Boston: The Castle (Fort Independence)

One of the most recognizable landmarks in Boston that does not fall along any of the city's historical trails is Fort Independence, which is known as The Castle.  The earliest fortification to stand on what is today Castle Island, just to the southeast of the city, was constructed in 1634 to provide a point of defense for the city against any attacks by sea.  The original earthworks were soon bolstered by a wooden structure, due in part to concern over a French warship which had approached the city, and that fort was enhanced or replaced multiple times during the following decades.  By the dawn of the 18th century a fifth version of the fort was constructed, which was named "Castle William" in honor of the English monarch who had taken the throne during the so-called Glorious Revolution of 1688.

Castle Island was an important location in the time leading up to the American Revolution, with its garrison serving as a secure shelter for British loyalists while unrest swept through Massachusetts, and after the battles at Lexington and Concord the fort became the main stronghold during the Siege of Boston.  When troops under the command of George Washington surprised the British army by successfully placing cannons and fortifications on nearby Dorchester Heights, both Boston and Castle William were unable to defend themselves and the British army withdrew.  Not wanting such a well-supplied and protected location to fall into the colonists' hands, however, the loyalist army set fire to the fort in an attempt to render it useless.  Troops led by Paul Revere, by then a lieutenant colonel, quickly repaired the damage.

The newly-renamed Fort Adams remained in colonial control throughout the remainder of the war and was controlled by the Commonwealth of Massachusetts for a number of years thereafter.  It served as a prison for approximately 20 years, and by 1799 it had been turned over to the US government and given the name Fort Independence.  An expansion of the fortifications that began in 1800 was apparently enough of a deterrent to potential attacks that during the War of 1812 no assault was leveled against Boston, despite a significant level of British naval activity in Massachusetts Bay.  Construction on today's pentagon-shaped fort began in 1836, although various challenges and repairs dragged on until its completion in 1861 at the beginning of the Civil War.

Control of Castle Island, but not the fort itself, was returned to Massachusetts by the US government in 1890 and the island was soon connected to the mainland during a series of large-scale land reclamation projects by the city of Boston.  In 1908 Fort Independence was also handed over to Boston's governance, where it has remained except during times of war.  The last military use of the location was during World War II by the US Navy and, despite being part of every significant conflict from the Revolution until that point, the US military has never been forced to fire a shot in its defense.  Today the state government and a non-profit organization oversee the site, operating tours and other events that help educate visitors on its historical importance.