Vault 101

Vault 101 is a location in the northwest area of Washington, D.C. It is found northwest of Megaton and west of Springvale. It is the home of the Lone Wanderer until they leave to search for their father.

Background
Outside the vault entrance on the road is a "Type B" random encounter location site. It can be activated by following the road south slightly past the elevated highway. The overlook outside the vault's entrance is the location for the animal companion Dogmeat after being recruited. They will go to this spot if dismissed as a companion. The overlook outside the entrance is also the destination of any slaves freed from the slave pen located in the train tunnel to the Pitt if they survive the journey.

Notable loot

 * Medicine bobblehead - In James' office, in the clinic.
 * Rock-It Launcher schematics and 300 caps - In James' office, behind an Average locked safe behind the framed verse.
 * Grognak the Barbarian - In the diner, from Amata. If not used during their party, it will be in the dresser before leaving the vault.
 * Stealth Boy - On returning to Vault 101, found on Steve Armstrong's corpse in the decontamination/security control station.
 * Pre-War toaster - Behind the counter in the diner.
 * Butch's toothpick - Carried by Butch during Trouble on the Homefront.
 * Modified utility jumpsuit - Given by Amata for completing Trouble on the Homefront peacefully.

Appearances
Vault 101 appears only in Fallout 3 and is mentioned in Fallout 4 and

Bugs

 * Closing the vault door manually using the exterior console will work normally during Escape. Approaching the tunnel exit will result in the Vault door reopening behind you exactly when it is supposed to close if you don't tamper with the console.
 * On the rocky overlook outside the entrance to the vault where Dogmeat is sent if disbanded as your companion, there is a chance that he will fall through the map and can no longer accompany you. This happens only when he is dismissed, not when traveling to the vault with him.