The Phantom Stage is Stage 28. Although they say the opera boxes are still in the stage, only the box seats on either side of the proscenium and a few levels of the opera remain. Still, an important part of movie history!
The interior of the Bates mansion for Psycho was built in Stage 28 and Arbogast landed in the exact spot where the chandelier crashed for Phantom (according to Mr. Hitchcock!).
All T-Rex scenes for JP2 were filmed in Stage 24 (or 25) because they were on tracks bolted into the concrete floor. Stage 28 has a wood floor.