A stairway or staircase is a flight or series of flights of steps and a supporting structure connecting separate levels. Elements of a stairway include stair tread width and noser shape as well as the stairway riser. Balusters, landings and stair walls may be involved. A staircase wall is called a cheek wall. Masonry stairs can be laid in brick or stone and involve pavers and bullnose projections.