RELIC 1

The first relic is in the plaza near the Valley Farmstead Base Camp. It's under the canopy behind the men examining a map spread out on the ground. Check the level map and walkthrough if necessary. (Click screenshot to enlarge.)

RELIC 3

Relics #3 and #4 are in the House of the Afflicted Challenge Tomb. You can follow the walkthrough to find them or, if you've already raided the tomb, return to the Infirmary Base Camp, go through the doorway to the north, and you'll find this relic sitting on a table in the hallway. (Click screenshot to enlarge.)

RELIC 5

This relic is in the building near monolith #3, in the southeast corner of the section of the valley that is accessible on the first visit. Go around to the other side of the building from the monolith to get inside. See the walkthrough and map for details. (Click screenshot to enlarge.)

RELIC 7

This relic is also in the Catacomb of Sacred Waters Challenge Tomb. On your first visit, follow the walkthrough. Otherwise, return to the Aquifer Cavern Base Camp, drop into the big room with all the skulls, and go up the stairs. Swim or use the zip line to cross the pool, and on the right, you'll find the doorway to the codex room. (screenshot) The relic is sitting on the floor just as you drop down into the codex room. (Click screenshot to enlarge.)

RELIC 9

This relic is also in the Pit of Judgment Challenge Tomb. To backtrack for it later, return to the Hidden Ravine Base Camp, follow the tunnel down to the main cavern, swim across the pool, and turn around to face the mine cart tracks. Climb the tracks on the right, using your grapple to cross the wider gaps. Then slide down the zip line. The relic is on the lower level of the wooden structure where the second mine cart was. (Click screenshot to enlarge.)

RELIC 11

This relic is hidden behind a wooden impact barrier a few steps northwest of the Ridgeline Base Camp. This camp is not accessible until you return from the FLOODED ARCHIVES level, but you can always return here later if you missed it. Again, see the map and walkthrough if necessary. (Click screenshot to enlarge.)

RELIC 13

Again, you'll probably want to follow the main walkthrough the first time you explore the Baths of Kitezh Challenge Tomb, but if you overlooked this relic, just fast travel back to the Whirlpool Sanctuary Base Camp, go through the trapped hallway to the northwest, and you'll find the relic sitting on a shelf on the left just before the stairs leading up. (Click screenshot to enlarge.)