...you're in the dungeon, baby. You're gonna diiiiiieeeee!
Well not really a dungeon, but my Fantasy arena with geomorphic tiles. Each 6 x 6 inch square is movable giving lots of variation. The whole thing gives 2 x2 feet of gameable area. Which doesn't sound like much, but is in fact, more than enough. I've been using a version of the Goal System game engine, where characters start out roughly the same with "upgrades" and traps scattered about. There's teleport squares and chances for bigger nasties to appear. Great fun for a convention or quick throw down.
all the pieces are made from 1" thick pink insulation foam. Just cut to size, score with a dull pencil to make tiles, bricks, etc. then dry brush. Whole thing took surprisingly little time.