373 steps

and 150m high is this Liège stairway named Montagne de Bueren. It was constructed around 1880.

 

Quite a climb, but you will be rewarded with a magnificent view on this Belgium city.

 

I actually found it quite difficult to approximate how one would perceive the enormous height of the stairs in real life, and still wondering what orientation and cropping would have been the best.

 

BB901.com: Montagne de Bueren

Done