Stairs can be straight, curved, automated, square, and crossed. They are all interesting even if looking down or up. Some can look like Escher designs, or just fabulous shapes.
Red SpiralUp and DownThe Eye StaircaseOld Stairs in LyonStaircase, Roman MuseumUpwardSpiral StairsGoing in CirclesSpanish StairsDown, Down, DownPalmer House StairsFigure EightStair GraphiccsStair CurvesSpirals in LiverpoolStairs in ChicagoStairwellDown the StairsCrossed Stairs