Trying to think of a stagecraft/theatrical term

Okay, imagine a large-ish stage. Most of the action occurs center stage where the stage remains the same throughout, but at the far left and far right visible areas of the stage are two slightly elevated platforms, but stationary*, that serve as ancillary stages as needed. They’re usually bare but may have a chair or prop or backdrop as needed. (Example: suppose the play is Hamlet- the center stage may remain the throne room of Elsinore Castle for the entire performance but the side stages may change from the graveyard to the battlement to just completely bare for the 2Bon2B soliloquy.)

Anybody know if there is a word for these little ancillary stages are called other than sidestages?

Thanks for any info or suggestions.

*Stationary meaning that they are there throughout the performance [they’re not embossed perfumed letterhead

Are you speaking of the wings?

Risers? My wife teaches drama, and I design and build sets; that’s what we call them.

Nitpick: the fancy paper is called ‘stationery’. This is because it was sold at a stationer’s. Stationers sold what we would call ‘office supplies’ to people working in railway stations, such as ticket agents, who were among the first large-scale users of industrially-produced paper, pens, and so on.

Okay, that explanation’s wrong. Apparently the term’s a lot older than that, and refers to someone selling at a stationary location, as opposed to a roving pedlar.

THAT’S IT!!! Thanks!