Periaktoi were revolving triangular prisms made of wood on the stage of the ancient theatre, bearing on each of its three sides a different pictured scene. They were usually placed to the right and left of the logeion on square frames and rotated around an axis, changing the scenery when needed. They represented places that the stage building could not represent (e.g. the countryside, the port). The periaktoi were revived, notably for the Renaissance theatre and for the 17th-century English stage.