Minerva Arts Centre is the town's textile stop, run by The Quilt Association in a building close to the centre. Exhibitions draw on antique quilts, contemporary textile art, local craft, and workshops, which fits Llanidloes' old wool and flannel history better than a generic gallery would.
Check what is on before you go. When the exhibitions are strong, Minerva gives a small town a surprisingly specific cultural reason to linger.