Jon Nicholas

Corrected entry: Early in the film, Frodo, Sam, and Gollum are camped out inside a diamond-shaped structure. When the structure is shown from the outside, the diamond appears taller and thinner than when shown from inside looking out.

Jon Nicholas

Correction: The upper edge of the diamond is built out as well as up, so its appearance changes a lot depending on the camera angle.

STP

Corrected entry: Throughout the three films, Mount Doom is always shown spewing lava from its summit. This suggests that the lava is full to the brim. When Frodo and company reach the mountain, however, there's a large, open door leading into the center of the mountain. There is no evidence that lava has ever flowed through the door. Once inside, the lava level is hundreds of feet below them, but moments before lava was still spewing out the very top of the mountain.

Jon Nicholas

Correction: It is quite possible as with any volcano that there are separate lava tubes at the surface, obviously the entire mountain could not be hollow because it would collapse in on itself.

Sol Parker