Did this once before, I liked the challenge and it gave me ideas of things to grab for making more terrain. So . . . here is another terrain picture, if you can identify the bits in the picture! Heck, if you can link to what the bits are or where they came from even better (if forum rules allow)
First and easiest one to me is the 'pillars' the platforms rest on are curlers like I remember my mother & sisters having when I was a teenager. I am not sure they are even made any more, but now I want to go to dollar store and see if I can find them (or maybe the wife has some old ones, never see her using them).
The top of the two buildings are take out containers, I am not sure if they are top or bottoms BUT I think tops, painted over and with some detail work done on the exterior. The one on the left has some thing attached to get rid of a flat space, and the one on the right looks like it has bars of some sort. It might be pretty easy to cut out the flat portion of a container like that, build a grid, paint it, and then put the clear plastic portion back on top.
The left tower looks like it has plastic clothespins with the spring removed and the two parts separated attached to the die of some cylinder.
The drill looks like it was home made, a screw put at the 'bottom' of a funnel or cone?