Completing the What We Left Behind mission in Arc Raiders has a couple of tricky steps, including tracking down multiple hidden Raider Camps throughout different regions. Tian Wen, Speranza's resident gun nut, wants you to head to these camps and salvage whatever you can find for her.
While one of these camps is really easy to find, the other two are much harder, so it's understandable that you need a little help—I know I did for the Bilguun's Hideout one. All that said, here's how to complete What We Left Behind in Arc Raiders.
On Buried City, search two containers in the Raider Camp beneath the Parking Garage
Your first step is to head to Buried City, specifically, the Parking Garage near Marano Park, towards the centre of the map. This is usually quite a hot area for arcs, including pops inside the building itself, so tread cautiously.
Once in the Parking Garage, you'll find a door you can breach in the south-west corner, revealing a zipline that'll take you to the bottom floor—a room mostly buried in sand. In the centre, by the makeshift habitation, are two raider containers you can search, one long case, and one bag just behind the corrugated metal.
On Dam Battlegrounds, search for anything significant in the South Swamp Outpost
This one is nice and easy. Simply head to the South Swamp Outpost in the west of Dam Battlegrounds, near Water Treatment Control, and look inside the main cylindrical building to find some documents on a table, marked with a yellow search icon.
On Spaceport, search for anything significant in Bilguun's Hideout, next to Container Storage
This one tripped me up for a while. Bilguun's Hideout is actually on top of the wall just to the east of Container Storage, towards the centre of Spaceport. You'll want to find the wall, then head south or north along it to the broken sections where you can climb on top. Once up there, you'll see the metal Raider Camp hanging off the side, so just head there and collect the yellow marked notes inside, completing the quest.
