Mount Doom, the one place where the ruling ring can be destroyed. I based this mainly off the movie, but the path is an important detail from the books. The top of the volcano lights up, though you can't see it in these pics because it's an official LEGO light brick and not very bright It's obviously quite a bit smaller than it should be, but it used all my dark bley/grey at this scale The bridge and mask are very accurate to the movie. In fact this is the most movie accurate Mount Doom MOC I've seen, though if you know of a more accurate one I would love a link
Here are some pics:
Hope you enjoyed looking, and comments or criticism welcome