Vault-Tec Headquarters

The Vault-Tec Headquarters building is located in the Vernon Square area of the Washington, DC ruins.

Building History
This was Vault-Tec's base of operations around the DC area. From this location (specifically, from the Vault-Tec Mainframe), you can learn where Vaults 87, 92, 106, and 108 are. This is helpful in the Optional portion of the quest Agatha's Song.

Enemies
The only resistance inside the building are the leftover security robots and a few turrets. The models inside are regular Protectrons, Sentry Bots, Robobrains and Mister Gutsies. Also, there is one special model of the Robobrain on the level where the Mainframe is. It is called the Masterbrain and is hostile towards you. You can turn off the Masterbrain, and all other security bots in the Headquarters, if you use the correct command on three employee terminals in the Mainframe area. Alternatively, you can destroy Masterbrain and use it to shut off all other security bots.

Super Mutants have also been found fighting the robots in the Guest Relations area. It seems they have been using the Vault-Tec HQ as a massing point, as Gore Bags, which are a common find within Super Mutant bases, are located in the Guest Relations men's restrooms.

Guest Relations

 * A Tales of a Junktown Jerky Vendor book on a table up the broken stairs on the right side of the room, in the cafeteria area. It is meant to only be accessible when you go down from Administrations again. However, with some with tricky jumping it can also be reached if you jump from the highest point of the broken staircase.

Corporate Offices

 * One Nuka-Cola Quantum is located in the most Northwestern room on the second floor. It is on the bottom shelf of a bookcase. There's a door covering a hole in the floor in this room.
 * A Big Book of Science in the room east of the room containing the Nuka-Cola Quantum on the second floor. The room with the book should have almost no floor. When you stand in the doorway and look straight through at the opposite wall, you will see two bookshelves slightly off to the right on the eastern wall. The Big Book of Science is on the top one. The easiest way to obtain it is to shoot it down.
 * Stealth Boy; northwest corner, top floor, in a storage closet just above the room with a random loot safe that also sometimes contains a Stealth Boy. (You have to walk around the edge of the missing floor to get to the closet.)
 * A Pre-War Book on top of a garbage can next to aforementioned safe.
 * Possibly a Power Fist or Recon Armor opposite the shelf that the Big Book of Science is on, in a footlocker on top of a big wooden shelf.
 * In the second floor ladies' room near the exit to Administration, there should also be a Scoped .44 Magnum and ammo hidden in the cistern of the second toilet from the end, on the left hand side of the bathroom.

Administration

 * An issue of Grognak the Barbarian on a curved desk in a private office. The room is at the very west of the area.

Bugs

 * Once you've destroyed the Masterbrain, you can shut down all the other robots, then you return to the Guest Relations area through the door on the right side that was unacessable before, now go back to the Offices through the door on the left and you might find all the robots you previously destroyed, alive and functioning (Sentry Bots keeps moving) though they won't walk,attack and neither show on the compass as enemies or friends. The funny thing is that if you've ripped them to pieces before, they'll appear like that. e.g. An Sentry Bot torn apart in half, with the upper part floating.
 * There'll also appear the option "Talk to" in each of the robots, though it's not possible to perform this action.
 * Following the bug listed above, you can kill all the robots you've previously killed, and you'll still get the experience and maybe even some scrap metals from searching the bodies.
 * It is possible for the PC to get stuck in a hallway barricade. On the second floor, southeast area, there's a pile consisting of a desk, filing cabinet, and shelving. Jumping onto the desk could get you wedged in, as there's a section of ceiling protruding downward that prevents your exit. (confirm Xbox 360)

Behind the scenes

 * Over the front desk right when you enter the building, suspended from the ceiling is Vault 101's door, as an example of Vault-Tec's technology.


 * On the Administration level there is an employee computer in which you can order Vault-Tec accessories. Upon selection of an item, the terminal will say that the item's cost has been deducted from the employee's salary. It is unlikely that you can acquire those items. When you select "Vault-Tec Bobblehead", it outputs: "Only Available to Executive Level Employee." While this may lead you to believe there is a Bobblehead located in the building, there is not. This instead likely refers to the Vault Boy Bobblehead that comes with the Collector's Edition of Fallout 3.

Related Quests

 * Agatha's Song

YouTube Videos
Locating Vault-Tec Headquarters lzpGSXalvNE