Formerly manned by soldiers from Echo Company of the 104th Infantry Regiment, the checkpoint was responsible searching vehicles for contraband, and were authorized to disassemble vehicles to thus end. When the Great War broke out, the checkpoint began broadcasting on emergency frequency RJ1138, calling all South Boston Army soldiers to its coordinates in a loop. As of 2287, the checkpoint has fallen under Gunners control, with an unnamed Gunner commander in charge of it.
The checkpoint is located directly west of the Castle and past the bridge just outside of the South Boston area. It consists of two structures, the main building guarded by two Gunners and a trailer where a single Gunner is often found resting. The trailer houses a sleeping bag and a mattress, as well as a Fat Man.
In the main building, there is a Master locked safe with ammunition and other containers with minor loot. Two beds and a weapons workbench are also available in this building. On the western side of the building, there is a cage that can be opened with a nearby Expert locked terminal. The cage contains a power armor station, a full set of power armor and a mini nuke. On top of the building lies a skeleton, next to a leveled combat sniper rifle.
- Guns and Bullets issue #7 - On a desk within the checkpoint building.
- Fat Man - Found inside the trailer.
- Leveled power armor - Inside the locked cage just outside the checkpoint building.
- One mini nuke - Inside the locked cage behind the power armor.
- Two fusion cores - One near the elevator to the highway, the other is pre-installed in the power armor suit.
- Chinese stealth armor - In a trunk.
- The power armor frame here yields a full suit of leveled power armor that maxes out at X-01 Mk I at level 28, quite in contrast to other full X-01 sets that reach a maximum tier of Mk III at level 47.
- The items (including the Fat Man) respawn faster than the Gunners do.
- When at this location, companions make comments.[clarification needed]
The South Boston military checkpoint appears only in Fallout 4.