Stairs connect levels, they are climbed up or down, they are commonplace, for some they are insurmountable. Mostly little noticed, stairs are a means to an end. But the purposes vary.
For me, the fascination of stairs lies in the graphic quality, the straight lines, especially when they are highlighted by sunlight and shadows, then broken up again and accompanied or even complemented by silhouettes. The human silhouettes give a certain context. They show people on the move, hurrying or relaxing during a break where the stairs serve as seats.