Installation Vista - The Astronomer's Crypt

On the way down the path, before you reach the corpse leaning against a stump, there's a wooden box sitting on a ledge on the right. Open the box for some supplies. Then squeeze through the crack in the stone wall into the hidden area beyond. At this point, your ing-game map is updated, showing that you've discovered the entrance to a crypt—one of many you'll encounter during your travels.

Enter the cave ahead to initiate a Challenge: Into Darkness. The goal is to explore 5 caves scattered around the Soviet Installation. This is number one. Pick the 2 mushrooms on the ground ahead and collect 2 magnesite ore deposits, one on the right side of the cave...

...the other on the left near the sealed-up archway. Then use your axe to break down the wall so you can get through the doorway.

Pick up 2 Byzantine coins in the next small chamber.

The next contains a mural (1/12) inscribed in Greek. If you've discovered all the other Greek writings so far, this should increase your proficiency to Level 3 Greek as well as giving XP.

NOTE: Although they do not count as documents in terms of collectible items, murals are recorded in the Documents section of your inventory. This particular mural is titled Kokkos, the Astronomer and can be reviewed in the Crypt Murals section of the Documents screen.

Continue along the tunnel until you can drop down to a lower level. Enter the cave on the left with the dripping water and icicles.

Go around to the right and jump from the end of the ledge to the slightly higher ledge on the far side of the room.

Mine some magnesite ore and then continue into the dark alcove to find a document (1/26), Kokkos, The Astronomer from the Crypts of the Founders series. Examine it for XP and Greek proficiency.

Drop down into the center of the cavern.

Go through the small opening in the ice wall...

...to find mushrooms, 2 Byzantine coins, and a container with cloth and another coin sitting on a ledge near a skeleton.

Return through the doorway in the ice and climb back onto the ledge on the right. Go through the archway into the main passage and continue downstairs to the left.

Where the passage widens, go through the rough archway on the left...

...and climb up three ledges to find 2 coins and hardwood.

Turn around and use Survival Instinct to spot another container on the high ledge opposite. Jump across to get it. Then climb back down, return to the main passageway, and continue to the left...

...to find the crypt proper.

Along with the remains of Kokkos of Nicea, there are 2 piles of coins, one behind the sarcophagus, one to the left (4 coins in all). Open the sarcophagus to receive an ANCIENT BOW PART (1/4) plus 3,000 Expedition credits. When you find the other three parts of this bow, you'll be able to build it at any base camp.