This guide, along with the annotated level maps linked below, should help find any coin caches you missed. If you are playing through this level for the first time, you may want to follow the main walkthrough instead. Unlike Survival Caches, coin caches cannot be unearthed until they are revealed on your map. So before you do any digging, you'll need to locate and decipher the monoliths that show where the coins are buried. Then you can use your in-game map to set a local waypoint/player beacon on each cache, which will help you locate it.
There are 3 monoliths in the Soviet Installation. All require various levels of Russian language proficiency. The monolith just down the hill to the southwest of the Communications Tower Base Camp and the Supply Shack only requires Level 1 Russian. Reading it reveals the locations of the first 3 coin caches on your in-game map. (Click screenshot to enlarge.)
COIN CACHE 1
The first cache is just southeast of the Communications Tower Base Camp and the Supply Shack. It's buried in the snowy area with chain link fence on the cliff's edge. Check the in-game map or annotated level map if necessary. (Click screenshot to enlarge.)
COIN CACHE 2
This cache is buried just outside the entrance to the Forge's Crypt, below the Hidden Refuge Base Camp and north of the Logging Camp. Check the map and walkthrough for details. (Click screenshot to enlarge.)
This monolith is near the Copper Mill Yard Base Camp. It requires Level 2 Russian proficiency. Examining it reveals the locations of the 3 coin caches shown below. These are detailed in the Logging Camp walkthrough since they are found in that area. (Click screenshot to enlarge.)
COIN CACHE 4
This cache is buried on top of the rock formation near the guard tower about halfway between the Logging Camp and Copper Mill Yard Base Camps. (Click screenshot to enlarge.)
COIN CACHE 5
This cache is inside the snow leopard cave (C4 on the map). The Sheltered Ridge Base Camp is just north of the cave entrance. Depending on when you return here, the leopard may be waiting on the branch above the cave opening. (Click screenshot to enlarge.)
COIN CACHE 6
This cache is just west of the cave (C6 on the map), where you cleared out the wolves for the Dangerous Territory mission. The cache is on a snow-covered ledge below the one where you found the Archivist Map. (Click screenshot to enlarge.)
The third monolith is close to the wolf den (C6 on the map) and the 6th coin cache, shown above. You'll probably notice the monolith before you have the Level 3 Russian proficiency needed to read it. Once you are able to decipher it, the 3 coin caches below are noted on your map. (Click screenshot to enlarge.)
COIN CACHE 7
These coins are buried between the elevated tank and the chain-link fence just southeast of the Logging Camp Base Camp. (Click screenshot to enlarge.)
COIN CACHE 8
To reach this cache, climb the tall rock formation above the first wolf den (C3 on the map). You may have already done this in the course of completing the Communications Breakdown Mission. The coins are buried about halfway up, near the wooden scrambling wall. (Click screenshot to enlarge.)
COIN CACHE 9
The final cache is buried just outside the entrance to the Astronomer's Crypt, below the Installation Vista Base Camp. See that walkthrough for details. (Click screenshot to enlarge.)
†UPDATE HISTORY: 4/24/16 - Page first posted online.
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