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The Vault - Fallout Wiki
Fens Street sewer
377160 20170615202918 1.png
Worldmap Loc Img 157.png
Map MarkerFens Street Sewer
Cell NameFensStreetSewerExt
FensStreetSewer01 (interior)
ref id0000e4ec
0003b381 (interior)

The Fens Street sewer is a location in the Commonwealth.


Beneath this unassuming manhole cover is a a gruesome history. Before the Great War, the Fens Street sewer was the den of a serial killer known as the Fens Phantom, who displayed his victims around the sewers. A detective investigated the sewer and tried to bring the Phantom to justice, but she too found her end in the Fens Street sewer.[1][2] Feral ghouls have since moved in, but the sewer is as dark and winding as it was 200 years ago.


Once down the ladder, a brick tunnel leads down to a partially flooded sewer floor. The catwalk at the end of the hall leads into another brick hallway, which heads to a room filled with radioactive barrels (peaking at 10 rads per second). A hall to the north goes past a small alcove into a space filled with baby carriages and the skeletons of mothers. A bridge leads across the water leads to a higher tier of the room; stairs lead further up into the sewer.

An earthen tunnel leads to a generator room, lined with catwalks. A stairwell in the middle of the room heads up to a tunnel that ends with another catwalk above the generator room. The catwalks leads back down to an otherwise inaccessible tunnel, which winds down and exits into the first room of the sewer.

Notable loot

  • An issue of Tumblers Today is found in the generator room, behind a security gate in the southwest corner. The magazine is on a cabinet.
  • Dear detective 1 is on a cabinet with some toys beside an hung skeleton, directly as one enters the sewer.
  • Dear detective 2 is found on a grill (along with a skull and some arm bones) after going past the catwalk in the first hallway.
  • Dear detective 3 is found after going across the bridge in the room full of baby carriages; it is on the end table beside an easy chair.
  • Dear detective 4 is found beside the Tumblers Today (detailed above).


The Fens Street sewer appears only in Fallout 4.


  1. Fallout 4 Vault Dweller's Survival Guide Collector's Edition p.432: "[9.06] FENS STREET SEWER
    In prewar times, the deeper areas of the sewer were secluded and difficult to reach. Time has exposed parts of the upper tunnels to the sky and Feral Ghouls have since moved in, attracted to the nuclear power sources of the water pumps below.
    An unassuming manhole cover and sprawled skeleton of an old sewer worker leads into this large labyrinthian tunnel system. When you find a series of skeletal remains, it becomes clear this was a place of suffering.
    Miscellaneous: Dear Detective
    The map shows the locations of four Holotapes with messages recorded on them. Listen, and figure out where the detective and her quarry finally came to rest."
    (Fallout 4 Vault Dweller's Survival Guide Map)
  2. Dear detective 1, 2, 3, and 4