The Vault - Fallout Wiki

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The Vault - Fallout Wiki
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Fallout: New Vegas locations project
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Big MT north tunnel
Big MT north tunnel.jpg
Icon metro.png
Big MT north tunnel loc.jpg
Map MarkerBig MT North Tunnel
QuestsAll My Friends Have Off Switches
Cell NameNVDLC03SLTunnelNorth (exterior)
NVDLC03SLTunnelNorthINT (interior)
ref idxx0019a3 (exterior)
xx006882 (interior)
Gametitle-FNV OWB.png
Gametitle-FNV OWB.png

Big MT north tunnel is a location in Big MT in 2281.


The north tunnel is a subway tunnel shaft with a door on the right of the entrance of the tunnel. Inside there is a hole in the floor, leading down into a subterranean cavern. The hole is guarded by an overclocked turret and covered with a force field that requires an upgraded sonic emitter to bypass. The cavern leads down a short ways with a group of crates with miscellaneous loot at the end.

Notable loot

  • Light Switch 02 personality tape, on shelf behind the door to the right of the entrance.
  • A LAER at the bottom of the cave in the tunnel.
  • Down the shaft there are 5 mutant cave fungus plants you can harvest.

Related quests


  • This is most likely the location where Elijah punched an escape route out of the Big MT using a train.
  • On the left front wall of the arch there is an Old World Flag painted in white, left by Ulysses.


The Big MT north tunnel appears only in the Fallout: New Vegas add-on Old World Blues.