The layout for Mass Bay is mostly vertical, except for the first floor which is broken into two sections and the second floor which spans multiple hospital departments. The first four floors are in a different interior cell than the other floors, so if all enemies have been cleared, the Sole Survivor can freely move around without alerting enemies on the remaining floors.
The main entrance opens into a 2-story lobby; the Sole Survivor will be facing east upon entering. To the south is a police protectron and the Expert terminal that controls it sits behind the nearby desk. East of the lobby are some broken elevators to the north and restrooms to the south. Further east are a kitchen and a fortified cafeteria with a cooking station and a Gunner who may be doing push-ups if one sneaks up on them. To the south of this area is another entrance into the medical center. Back to the lobby, to the north is a set of stairs leading to the second floor, but is blocked beyond that.
The other part of the first floor consists of the emergency room entrances and lobby. The main emergency room entrance is to the west, and another entrance can be found across the room to the east. To the south is another broken elevator which houses a turret. Near the elevator is a staircase leading to the second floor.
Starting from the main entrance staircase, to the south is an Assaultron and/or a leveled Gunner who patrols the area. From this main area there are paths to the east, southeast and south. Southward is the emergency side of the hospital, including the staircase down to the first floor to the west and exam rooms to the east. To the east is another small lobby and multiple exam rooms, one of which has a chemistry station. Further to the east is a medic protectron controlled by a Novice terminal right next to it. There are two locked exam rooms - one is Expert-locked and contains a gruesome scene, the other is Novice-locked and has an addictol.
Back to the main area, the eastern path closest to the staircase leads down a hallway which curves to the south. Around the corner lies another turret protecting yet another entrance into the medical center. This entrance is reached by taking the wooden stairs that circle the building on the outside.
Main area - the southeastern path leads into a room with two cells, one of which contains a dead minuteman. Behind the nearby desk is a Novice terminal which can open the Novice locked safe just below. Continuing on leads one into a room where the third floor has collapsed, creating a path up. It also contains several curtained-beds which contain various things like a chemistry station and ammo.
Going up the collapsed floor path leads to some rooms - two lab-type rooms and a small office. Beyond this is another reception area with two broken elevators and the creepy baby in a carriage. The staircase that was blocked from the second floor is now clear and can be used to reach the fourth floor.
Yet another reception area. Here there are doors leading to a new area, Medical Center Station North, and a working elevator. Take the elevator to continue.
The elevator opens up to the seventh floor. The floor goes to the right of the elevator, or east, and opens up into a three-story atrium. Be prepared, there is a Gunner commander on the eighth floor directly east who will try to enter a suit of power armor just north of them if one is detected. There is also likely another Gunner on the ninth floor. Various collapsed floors create ramps leading to the next story in the building. Take seven to eight, then to nine.
There is one thing of interest on this floor - power armor. If you're lucky you can take the whole frame, which is a T-45 missing the helmet. There also happen to be two power armor stations.
At the top of the ramp coming from the 8th floor is a bed. To the west on this floor are some more cells. One contains a dead Brotherhood of Steel scribe. To the east is a room with a collapsed ceiling heading up or a hallway leading further back. If one heads back, one will find an MRI machine and some offices, one of which contains a Novice safe. Once done with the area, the player character may take the collapsed ceiling to the tenth floor.
Not much of note on this floor, other than the elevator leading to the roof.
On the roof is a small living area with various junk items and drugs, and a u-turn from the elevator leads to a MILA drop point. There is also a window cleaning elevator that leads to the Ticker Tape Lounge. One can also see the Vertibird that crashed into the building, which created a path to the other roof with nothing of interest.
- Syringer - on a countertop in the northeast corner of the second floor.
- Vault-Tec lunchbox - on a couch next to a baby stroller, in the waiting area on the third floor.
- 動力裝甲 - 在八樓。附近有兩名槍手，如果偵測到玩家存在可能會穿上它。
- 邦妮的全像卡帶 - 在九樓東北角的MRI掃描室的控制台上。
- The chest x-rays are all hung backwards, with the heart on the left side. They are normally hung as if facing the patient, with the heart on the right. An x-ray can be taken from the front or back, with an "L" or "R" placed in the corner to show orientation. The artist seems to have hung this x-ray so the "L" reads forwards, rather than putting the "L" on the right. This is also a very common error in the entertainment industry (see Nicole Kidman's scene with Tom Cruise in "Days of Thunder" when, after his crash, she ponders his flipped x-ray before declaring him fine).
- On the third floor there is a grotesque scene involving a child's skeleton in a baby's carriage. The child's skull has been replaced with an adult skull and a baby bottle placed in its mouth.
- On the top-most floor, there is a window cleaning elevator that can allow access to the Ticker Tape Lounge. However upon entering the Ticker Tape Lounge and returning, the elevator will have returned to the top with no way of calling it back down. Simply fast travel out of the location, if the elevator "disappears."
- There is a crashed Vertibird on the roof of the building with cockpit stuck in the ceiling of the 7th floor.
The Mass Bay medical center only appears in Fallout 4.
- The scene in the room containing the flamer (2nd floor), consisting of a mannequin filled with med-X needles, a pile of ash, and several skeletons, is a reference to a scene in the book Fahrenheit 451.
pc Sometimes, when one enters the elevator to the roof and presses the elevator button, the elevator will close but then run forever, seemingly passing unlimited floors without end. 表达式错误：未预料的<操作符
- This may be related to the positioning of the player character and their companion when starting the elevator. Having your companion get in first and move to the back of the elevator, and then issuing the stay command, will normally prevent the bug from occurring. The elevator should pass about four floors on a regular trip - if yours goes beyond 5 or 6, you've likely encountered the bug. Jumping around inside the elevator might cause it to become "unstuck."