MONOLITH 1

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 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.)

MONOLITH 2

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 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.)

MONOLITH 3

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 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.)