There are only 4 murals in the valley. This guide, along with the annotated level maps linked below, should help find any murals you missed. If you are playing this level for the first time, you may want to follow the main walkthrough instead.
This mural is between the village and the Architect's Crypt to the northwest. You'll find it on the back of the square, ivy-covered pillar that has document #11 on top. See the walkthrough and level map for details. (Click screenshot to enlarge.)
This mural is inside the Architect's Crypt, behind the waterfall on the northwest side of the valley. Follow the main walkthrough if you need help finding the crypt entrance. The mural is on the left side of the dark tunnel just before the zip line that leads down to the crypt proper. (Click screenshot to enlarge.)
This mural is in the tower workshop belonging to the Remnant herbalist who gives you the Ancient Secrets Mission. It's on the east wall opposite her worktable. Both the herbalist's tower and the mural itself are marked on the map, and the walkthrough includes details. (Click screenshot to enlarge.)
This mural is in the Physician's Crypt on the southeast side of the area. Check the walkthrough and map for help locating and entering the crypt. Once inside, follow the tunnel. After sliding down the zip line, look for the mural a little farther along on the left. (Click screenshot to enlarge.)
†UPDATE HISTORY: 6/11/16 - Page first posted online.
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