The stairways are spread throughout the city, but are most heavily concentrated on the South Side, along the Monongahela River.
A quick scan of the city’s topography shows why these stairways are such a crucial piece of infrastructure, dotting the ridges of hills too steep for traditional sidewalks or roads.
The history of the steps is closely tied to the history of the city. The bulk of the steps were constructed in the 1940s and 1950s, a period during which Pittsburgh's population peaked and the steel industry thrived.
The staircases come in many sizes and shapes, with some cutting sharply up hillsides between streets and others winding alongside hilly roads.
Approximating their heights based on the number of stairs allows us to get a sense of their slope, with the steepest nearing a 70% grade. This is almost twice as steep as Canton Avenue, the steepest road in Pittsburgh and in the United States, which has a 37% grade.
Stacked one on top of another, the steps would rise over 24,000 vertical feet, nearly twice the climb from Mt. Everest's basecamp to its peak.