This massive Mega Mansion was constructed to serve the wealthy Garrahan family as a seat of power - just opposite the Garrahan Mining Headquarters. From their perch high above the misery of the Ash Heap, the Garrahans tried to confront the rising influence and might of their competitor, the Hornwrights.
The vast tower contains five levels worth of loot. The exterior of the mansion on the ground floor leads to the entrance, with an elevator. A keycard is required to enter the elevator, and three can be found at Garrahan Mining Headquarters, located across the road to the south. One is on the desk in Vivian Garrahan's office, another on the desk in the small side office in a nearby admin area, and the third laying on a machine next to the service door at the lower end of the underground railway accessed via the R&D section.
The elevator can be taken to the lowest or central level of the mansion. The lowest floor contains sloth cages in the east and the kitchen in the west, together with a small lookout lounge and bedroom in the northwest. Just up the stairs lies the second floor. This floor contains the game room and the bar and lounge on opposite sides of the floor. In the central section is Bill Garrahan's bedroom and a firing range on the southern face, which contains a security cage with a weapons workbench, some ammo and a high level minigun spawn.
The third floor belonged to Bryce Garrahan, with his office and lounge in the western part, and his bedroom in the eastern. His bedroom contains a locked safe and a tinker's workbench. On the fourth floor are the main music and dining room in the western part, with an adjacent kitchen and guest bedroom. The other end contains another bar and music room. This floor shares the central foyer with the third floor.
The fifth floor contains the living spaces of Vivian Garrahan in the central area (with a locked level 3 closet, a locked safe and a private bathroom), with another bedroom on the southern face. Upon the grand roof deck is the main hall. There is a bar at the eastern end, a kitchen and a flying car model that one of the Garrahans was working on, and a jacuzzi-filled open deck to the west.
- Isaac's message to the Sloth - Holotape, on the radio in between two dirty desktop frames behind a couch on the third floor.
- Can't find the keycard - Note, on a table in front of the elevator on the first floor.
- Assaultron recall keycard - In Wolf's cache on the top floor.
Garrahan Estate appears only in Fallout 76.