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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Mysterious cave
Mysterious cave.jpg
Icon cave.png
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Map MarkerMysterious cave
Cell NameNVDLC03SLBloatfly (exterior)
NVDLC03SLBloatFlyCave (interior)
ref idxx0019a2 (exterior)
xx01507b (interior)
Gametitle-FNV OWB.png
Gametitle-FNV OWB.png

The mysterious cave is a location in Big MT in 2281.


It is located south-southeast of the Big MT north tunnel, southeast of the Forbidden Zone Dome entrance and west-northwest of Elijah's Watch. It has nearly exactly the same layout as Broc Flower Cave, without the radioactive barrels and lit torches. Upon entering the cave, the player must choose to go left or right. To get to the bottom most part of the cave, where there will be a cavern quite large where the legendary bloatfly lives, you must go left. Going right offers a little loot, a cot for the player to sleep and just a few bloatflies. Going to the right also provides you the perfect position to go for the legendary bloatfly, with an overlook (you can reach it via a hard to find way on the east of the larger cave you entered, it is before the cot).

The mysterious cave is most notable for the legendary bloatfly, one of the most powerful creatures in the game. Upon slaying it (if you can) and searching its remains, you will get a substantial amount (roughly 50) of bloatfly meat along with other random loot such as Buffout and Psycho.

Notable loot


The mysterious cave appears in Fallout: New Vegas add-on Old World Blues.


  • PlayStation 3Icon ps3.png Xbox 360Icon xbox360.png The map marker on the compass will only appear when at the Forbidden Zone Dome entrance making it difficult to find the cave.