Nice article here about a bit of theater magic -- a set transformation that happens during the intermission that speaks volumes about the story. A stage picture is worth a thousand words, or something like that.
My brother told me, once, about a production of Who's Afraid of Virginia Woolf? that he saw back east, where in each act the set was more broken and spare than the last, so the end of the play was done on practically a bare stage -- an idea that knocks me out just to think about.
I remember a pivotal production of Bent that I saw in Portland when I was in college (pivotal for me as a writer and a human being)... I'd hardly been to a play before, not really. Not if the ones I was in myself in high school don't count. It was a small theater. During the time when the hateful Measure 9 was being hotly debated everywhere. And the small theater had been transformed into pre-War Germany -- flags on the walls around us, tinny German music, as if over a phonograph, and two Nazi soldiers positioned behind the audience for the duration of the play, as if we were held prisoner in the story ourselves.
What's your favorite use of set or space to tell a story for the stage?