The terrain piece itself (and the wall behind it) I downloaded from a website that offered textured terrain. Plotted it on mylar, and glued fender washers to the bottom. It is very sturdy, does not get moved easily during play, and looks better than the plain stuff provided by the company that makes MW.
I glued tiny hinges inside that wall (hard to bend mylar!). I can make it exactly 1/2" across the base this way, as is the game standard. I will later buy and paint a better wall.