Concrete Stair with seating
Massimiliano Fuksas, Staircase Armani Fifth Avenue, New York
Art Nouveau Staircase by Victor Horta -Hotel Tassel, Brussels. Typically of this period the interior has elongated, curved and flowing lines. These lines are seen in the tiles, the staircase and also on the walls.
i would have one long staircase just going up, and one even longer going down, and one more leading nowhere, just for show!