In reality, it is a very long staircase with 133 steps. On the map (in Street Complete) you can see several staircase segments that are directly behind each other. However, as there is no boundary between the stairs on site, the number of steps cannot be assigned to the individual sections. That's why I had the idea on site to simply merge the staircase segments and make "one staircase" out of them. 
I just tried that, but couldn't find a way to combine the individual segments. 

It was primarily a matter of answering the question about the number of steps, since - as I said - it is rather difficult to assign them on site.