Geothermal Valley - Cathedral Courtyard Base Camp

Move out onto the ledge at the front of the building overlooking the bonfire. Turn left, jump off the little wooden ramp, and press Interact to deploy your grapple axe, catching the wooden handhold on the wall below the statue. Now use a combination of regular and axe climbing to reach the top of the wall.

As you enter the ruins, it starts to rain. Stay alert. There's a lynx enjoying its dinner on the broken bridge ahead. If you have the Animal Instincts skill it will glow in Survival Instinct view.

Stand at the top of the stairs and shoot it with 2 poison arrows in rapid succession to weaken it.

Then, as it leaps down and comes up the stairs on the left, switch to the shotgun...

...and take it down as it charges. Be sure to skin it for exotic hides. (Alternatively, 2 grenade arrows can kill it before it even has a chance to jump down, but you may want to save those for tougher enemies later on.)

Continue down the stairs to find a document (28/33), The Visitor from the Diary of the Resistance series (Greek), sitting on a crate near the Cathedral Courtyard Base Camp.

Dig up a survival cache (16/20) tucked away in a corner about halfway along the south wall. (This is one of the caches revealed by the Explorer Satchel near the Aqueduct Ruins Base Camp. Use your map if you're having trouble finding it.)

Move up the broken bridge and loot the lynx's kill for deer hide. Then climb the stairs to the northwest corner to find a box with a relic (10/13) an Arrowhead from the Early Inhabitants set.