The Castle

The Castle is the former/current headquarters of the Minutemen in Boston in 2287. It is built into Fort Independence and is located on the East of The Gwinnett restaurant and brewery.

Background
Before the War, it was known as Fort Independence. The Minutemen repurposed it as their headquarters in the Commonwealth until a colony of mirelurks forced them out and took it as their nest. Preston Garvey wants to reclaim the Castle for a new generation of Minutemen.

Once the main stronghold of the Minutemen, The Castle is a potential settlement for the player, but it is teeming with mirelurks and houses a mirelurk queen. These enemies must be defeated before the player can begin to build and attract settlers.

Layout
Fort Independence is a star fort, consisting of five triangular bastions connected by walls. The walls are hollow and contain most of the fort's infrastructure, with only the workshop and the Radio Freedom transmitter out in the courtyard and two ruined gun positions on the walltop. The northwest and southwest walls have been all but demolished, and a sizable hole punched in the south wall as well, cutting off the west bastion--which contains the Castle armory--from access excepting through the Castle Sewers. The north bastion contains the Castle kitchen; the east, the General's quarters and access to the Castle Sewers; the southeast, the barracks. The southwest bastion is completely inaccessible.

The Castle is initially occupied by a large group of mirelurks, and piles of mud studded with mirelurk egg clutches can be found all over the courtyard and all interior areas save the armory. Once the quest Taking Independence is completed, these will be cleared away and the fort made available for settlement.

Inside the fort is a missile launcher and flamer, as well as a small amount of ammunition for each. Once settled, it comes with five free beds, a medic stand, chemistry workbench, starter lighting and electrical cable system, and an industrial water purifier good for 40 units of water should the player reintroduce power into the system.

Inside the Armory is a cache of heavy weapons, a weapon and armor workbench, and 3 free laser turrets that can be stored or redeployed elsewhere using the workshop. Also present are the schematics for building the special artillery piece. However, access to the Armory is impossible until the quest Old Guns is completed.

Access to the Castle settlement is done from the south via the main gate, and enemies will attack from this direction; behind the gate is a small and highly defensible room, which combined with the Castle's high and easily repaired walls makes it one of the safest settlements in the Commonwealth.

Notable loot

 * Guns and Bullets magazine on the radio operator’s desk, in the middle of the Castle grounds, outside. Confirmed during Old Guns mission.
 * Fat Man in the armory accessible during/after Old Guns
 * Various laser musket upgrades in the armory

Appearances
The Castle only appears in Fallout 4.