Entrance coordinates: [712478; 3416187]
Note: You'll able to explore this tomb only after receiving the climbing axe from Roth in Cry for Help. The game itself will suggest you explore it as soon as you get close to it while making the ascent towards the waterfalls. The entrance is located near the bridge not far from the wolves' cave, to the right of the waterfall. Before going in, pick up the GPS Cache.
Once you're inside, approach the interactive wall and use the climbing axe on it (that's why you need it). Light the torch and head through the tomb. You don't need to keep an eye out, there's nothing of value to find here.
You'll reach a new base camp where you can rest (not mandatory, though). Head north, through a small waterfall, and you'll enter the tomb's main room in which you'll have to solve a simple puzzle.
Stand in front of the platform with three cocoons.
Jump over to it and immediately jump again, this time to land on the shelf with a lamp. Use it to light your torch.
With it, go back to the platform with three cocoons. Ignite one of them.
Backtrack to the starting point and push the cage on the right.
Stand in front of the platform with cocoons again. Jump across and climb it.
Turn left and jump for the last time. Be ready to quickly tap the action button to have Lara automatically use the climbing axe. Climb to the top ledge (reward: 250 XP).
Examine the area and you'll find a large crate. Open it. It contains 250 Salvage points and a map of Relics and Documents (reward: 1250 XP). Backtrack to the exit.