The Railroad moved their base of operations to the catacombs under the Old North Church after their old headquarters at The Switchboard was raided by the Institute and they were forced to flee the complex through an escape tunnel. Many of their operatives and members died or fled and the Railroad was almost disbanded.
The entrance is hidden and can only be opened by following the "Freedom Trail," solving the puzzle and inputting the solution using the rotating wheel at the hidden door. The crypts may be dark, but they offer protection from attacks and prying eyes, and allow the Railroad to keep functioning.
After the Sole Survivor joins the Railroad, they are given free rein in the HQ. There is big circular table in the middle of the chamber where Desdemona usually lingers. Left of the entrance is Doctor Carrington's area with medical supplies and a treatment bed. In the far right is Tinker Tom's corner with research equipment, a terminal and a firing range. On the other side of the circular table is a rest area where Drummer Boy and Glory can be found (Deacon will also be here if the Survivor chose not to take him as a follower or elected not to send him to a settlement upon dismissal). On the right side is P.A.M.'s chamber with several large computers and her terminal on the table in the lower section.
There is a chalkboard on the wall showing all of the railsigns.
It is revealed that there is another exit from the crypts to the side of the rest area, which also serves as an escape tunnel, and leads directly to the surface north of the church, to a ruined building with a chained up door.
- Astoundingly Awesome Tales - On the desk directly west of the circular stone table in the middle.
- Blackbird report holotape - Can be pickpocketed from Doctor Carrington.
- Fusion core inside a generator in the "secret exit" from the HQ, behind the security door locked by an expert-locked terminal.
- A single set of mole rat teeth, this is the only location where a set can be found.
- The unique lab scale can be found on a metal shelf near Tinker Tom.
- Fatigues - Worn by Desdemona.
- Tinker headgear - Worn by Tinker Tom.
- Tinker Tom Special - Sold by Tinker Tom.
- Prototype railway rifle - Used by a Railroad agent that is helping Tinker Tom test it.
- Despite ample beds as seen in the back room, some Railroad members will sleep on the same mattress.
- Railroad HQ is one of the few interior locations the Sole Survivor can fast travel to and from.
- Leading X6-88 right into the Railroad HQ will cause the Railroad to automatically turn hostile. The same does not apply to Paladin Danse.
- One does not need to follow the entire trail in order to input the code, cutting down on time spent on subsequent playthroughs.
- There's a Railroad agent marking down several Morse code signals at a ham radio. The translated messages read:
- "Capital Wasteland Available for Delivery" – synth(s) ready for transportation to the CW.
- "Package Lost Raiders Repeat Raiders" – lost a package (escaped synth) to raiders.
- "Gen 1S Salvage Team at Baseball Tango 8" – Gen1 synth salvage team at location BT8, perhaps the WRVR broadcast station.
- "Dead Drop Disco Needs a Pickup Urgent" – a synth needing an urgent rescue.
- PC Playstation 4 It is possible to become stuck when standing on the white round table in the middle of the main room.[verified]
- To fix this, crouch and walk away, reload a previous save, or fast travel to a different location.
- PC In the later missions, it's possible for the main door to close without being able to be opened again.[verified]
- PC If power armor is docked in the power armor station it might become corrupted, this will cause pieces of the power armor to go missing and it will be impossible to exit the power armor whilst in the HQ. [verified]
- Xbox One There is a bug whereby Railroad missions will suddenly fail, and upon returning to Railroad HQ, they will all turn hostile. This is not a state of formal hostility unless or until the Sole Survivor returns fire.[verified]