Which preposition to use with proscenium

of Occurrences 2%

I forgot to mention that there is an inscription with that name on the side of the proscenium of the theatre easily legible by the light of flambeaux.

into Occurrences 1%

Doors opened from the proscenium into the retiring-rooms of the actors, under which were the vaults where the beasts were kept.

with Occurrences 1%

[They enter a small room, at the further end of which are a barrier and proscenium with drawn hangings.

Which preposition to use with  proscenium