The Fallout 76 mysterious cave code is a random code that helps you get into Vault 79. The cave code itself is completely randomized, and it is a different set of numbers for each and every player. So instead of outright giving you the code (we really wish we could!), this guide will tell you where to find the map six fragments to get the code.
To get the fragments, you’ll have to do a little hunting and a fair share of schlepping around the wasteland. Luckily, it’s mostly worth it as you’ll get to enter the previously-closed Vault 79.
The upstairs room of the Grafton Pawn Shop will give you clues for finding the pieces you need, but we’ll tell you where they are in case you don’t want to solve the puzzle yourself.
Each piece of the map is in a sealed manila envelope. You can do these in any order that you wish, but we will be going clockwise around the map.
Where to Find the Fallout 76 Mysterious Code Map Fragments
Mysterious Code Map Fragment 1
This map fragment can be found in Morgantown High School. Obviously located in Morgantown, the high school can be found on the northern edge of the city. It is almost due east of the Morgantown airport and south of Grafton Dam.
Go to the top floor of the school and look for the classroom above the school’s kitchen. The envelope is on a desk in the back of the room. There is a red swivel chair in front of the desk and a broken monitor on the desk.
Mysterious Code Map Fragment 2
This map fragment can be found at Red Rocket Mega Stop. This location is in the northeastern portion of the Savage Divide North region, directly south of the Baily Family Cabin and northwest of Vault 94.
Go inside the main building for the Red Rocket station and grab the envelope with the fragment off of the counter inside. It will be next to a radio emitting a light.
Mysterious Code Map Fragment 3
This map fragment can be found at Haven Church. This is located on the extreme eastern side of the map in The Mire. It is across the river from Treehouse Village and south of Dyer Chemical. It is northwest of the Abandoned Waste Dump.
Go inside the long building jutting out from the side of the church. The envelope is on another desk, which has filing cabinets and orange swivel chairs behind it.
Mysterious Code Map Fragment 4
This map fragment can be found at The General’s Steakhouse. This is located in the northeastern portion of the Cranberry Bog. It is right next to Firebase LT and just northeast of Mac’s Farm.
Go inside the steakhouse and make your way to the bar. The envelope will once again be on the counter near the cash register. There will be a post between the envelope and the cash register.
Mysterious Code Map Fragment 5
This map fragment can be found in the Uncanny Caverns in the Ash Heap region. This location is just northeast of Lewisburg and south of Relay Tower Dp-B5-21.
Once you get there, go inside the building with the gift shop sign outside and grab the fragment off of the counter near the cash register.
Mysterious Code Map Fragment 6
This map fragment can be found inside the Mothman Museum, which is located in Point Pleasant. This is in The Forest region on the extreme western edge, west of Marigold Pavillion, northwest of Hunter’s Ridge, and southwest from Black Mountain Ordnance Works.
Go inside the Mothman Museum and grab the fragment off of the desk directly in front of you. It will be next to the cash register.
How to Get the Pin
Now go back to the pawnshop and place the map fragments on the right side of the room. Turn on the black light to get the code.
Vault 79 Location
Vault 79 is located in the mountains north of the Baily Family Cabin. Look for a cave opening going into the mountain. The rock around the cave opening will have great vines growing all over it.
Header image source: Fallout wiki