I just came back from Shakespeare's Scottish Play "in the ruins" in Ellicott City...but not just IN them, like normal, where the actors play on them, and you sit in a seat, but you wandered around them, sorta chased actors or were chased by them (and herded from scene to scene to different locations up and down stairs, through narrow doorways -- this is not ADA accessible).
If you go, when they have you go UP into the building, and then invite you "down to lady mcB's fireplace" (the zone with chairs) -- stay on the balcony area -- much better viewing from there, even if you have to dodge actors. Actually, especially because you're dodging the actors.
http://www.chesapeakeshakespeare.com/macbeth.html has more info -- runs till Oct 26. And despite them claiming it's 90 minutes, it was more like 2.5 hours total, from leaving the parking lot up to the hill, and including an intermission.
Some of the coolest parts are the "offstage" murders -- you see some of them, but at a great distance, or out of a shadow. It's an excellent use of space. You can definitely feel like you're the ghost haunting the ruins, even if a disney-esque tour guide is inviting you to move to a new area.