Soviet Installation - Difference of Opinion
Burn 7 posters.
This challenge cannot be completed until you acquire Fire Arrows, but Molotov cocktails can do most of the job. Poster #1 is inside a large building by the trains. As you climb to the upper area, look for a rope arrow door you can open. The poster hangs on a wall on the other side.
Right after you learn to craft Molotovs, look to the corner of the area for a flammable barrier atop a platform. Burn through this to reach the poster on the other side.
When you reach the room with chutes, look for a rope arrow door you can yank open. Slide down the chute and take a leap at the end to climb onto the upper floor of a building you couldn't reach before. The poster is up here.
Back in the chute room, walk out onto the fenced-in deck and turn around to spot this above the entryway.
As you near the final section of the mill, keep an eye out for this poster hanging from a window.
From Poster #5, climb back down the previous ladder and leap across to the ledge pictured above. The poster hangs on the wall of that deck.
You can burn the final poster during the top-of-the-mill firefight. Look for it on a walkway right after you crawl into the final room.