Move through the cave and look for some [SALVAGE] near the skeletons to your right. Fat chance you'll find [RIFLE PARTS 1/3] here. Make your way into the windy tomb at sit down at the day camp to create a [RECURVE BOW] if you haven't already done so. Proceed over the bridge to reach the puzzle part of this tomb. It's not too difficult; the solution is below:
1. Close the shutters.
2. Move to the valve in the middle.
3. Wait for the first shutter to break open.
4. Immediately turn the valve.
5. Climb the platform and leap onto the platform attached to the ceiling.
6. Wait for it to swing over to the ledge; make the leap to reach it.
7. Use this wooden beam to reach the previously inaccessible platform. [250 XP].
Hall of Ascension Tomb puzzle solution.
Inside the treasure chest you'll find the [MOUNTAIN VILLAGE GPS CACHE MAP], and you'll also get [HANDGUN PARTS 1/3], [250 SALVAGE] and [1250 XP]. Return to the mountain village to continue with the game.
Make a rope bridge to the leftmost platform first; you'll find an [ILLUMINATION STATUE #6] here, and if you drop down to a lower adjacent platform you'll also find [EGG POACHER #3]. Move over the tree bridge to collect the [RELIC - #2 SEMPER FI (OLD PHOTOGRAPH)]. From here you can either backtrack to the ledge you were on before by jumping over the stream and climbing the wall (no need to), or you can create a rope bridge to the center platform of this area with a tree trunk that has some rope around it, where you can find a [GPS CACHE]. For now, do neither, but head back to the illumination statue #6 on the north side of the area and create a rope bridge to a platform with a hut to the east (close to the rock wall and waterfall) to find a document on the table here: [DOCUMENT - #3 ANCIENT SCROLLS (HOSHI: ANSWERING THE CALL)].
From here, create a rope bridge to the closest platform (to the west) with a tree trunk with some rope around it. Scramble up the wall to find another [DOCUMENT - #4 ANCIENT SCROLLS (AMBASSADOR: DARK TIDINGS)]. Carefully look down at the rope attachment pole to spot [EGG POACHER #4] on the lower platform. Create a rope bridge to the platform west of here (plug a rope arrow in the tree trunk) and move over. You'll find some [SALVAGE] here, as well as another [ILLUMINATION STATUE #7] around the other side (where you can create a rope bridge right back to the platform you came from, which is also where you need to go.)
: In order to backtrack to collect any missing treasures in this part, you must create a rope bridge from the southeast platform (where you found a document and some eggs) to the center platform (with a tree trunk and a gps cache). It's NOT possible to jump from the southWEST platform to the center platform; it's a surefire way to commit successful suicide.
Also note that the other two GPS cache locations on your map (which may confuse you) are located far down below and cannot be obtained at this moment.
From the southeast platform, create a rope bridge to reach the pilot's blue smoke signal. [200 XP].