The city of Pittsburgh in Pennsylvania, the United States, is located over an unruly terrain of hills, hollows, valleys and three intersecting rivers. Back in the late 19th and early 20th century, when Pittsburgh was growing as a coal and steel town, factory workers built houses in the hills rising above the flat riverbanks that were lined with factories. In order to commute to work, city officials and residents built staircases along the mountainside, originally of wood and later with concrete that ran up and down and all over creating a chaotic place that is notoriously difficult to navigate.

Revered American journalist Ernie Pyle famously wrote about the city in 1937:

Pittsburgh is undoubtedly the cockeyedest city in the United States. Physically, it is absolutely irrational. It must have been laid out by a mountain goat... I've flown over it, and driven all around it, and studied maps of it, and I hardly know one end of Pittsburgh from the other... There's just one balm -- people who live here can't find their way around, either.

Steps on Fannel Street.