OK, this is not a self-made terrain... and it's not even a terrain, just pieces of sceneries. However, i would say it qualifies, as i went through a search in the Big Boxes of Free Bits in our gaming shops, and scattered among various things, i found some very interesting and unused items: which i took and painted:
and after some glueing and rust effects, here's the completed scenery pieces: Steel pallets, with crates of ammunitions and oil drums (and an antitank obstacle)