You can find some [ARROWS] near the camp. First light up the area somewhat by shooting burning arrows at the various torches hanging from the wall. While this is optional, it does make navigating the area easier. Shoot the barricaded area up above (which immediately fills up with gas afterwards) by using a burning arrow. Immediately climb up, turn left and climb on the upper walkway to find some more [ARROWS]. Look across the area with Survival Instincts and you'll easily spot the climbable wall right in front of you. Before climbing up, first shoot the debris on top with a burning arrow to clear the path. Leap across and head to the top to reach this tomb's treasure chest. [1250 XP], [250 SALVAGE], and a [SUMMIT FOREST TREASURE MAP] is your reward.
Stormguard Sanctum Tomb solution.