These scrap walls are the siblings of the scrap gate I bought as part of the first batch of Crooked Dice terrain I bought. I liked the gate so much I needed to get more.
The four wall pieces are each unique, with a mix of posts, barrels, crates, and tires.
I painted them simply, with just a few common colors repeated. An oil wash really makes them grimey.
I was thinking about Fallout when I bought these, but like most post-apoc it would work in a variety of modern or near-future settings.