"In 1937 newspaper columnist Ernie Pyle wrote “[Pittsburgh] must have been laid out by a mountain goat. It’s up and down and around and around and in betwixt.” The stairs were built to help pedestrians navigate this daunting topography before the age of the automobile. In total there are 712 sets of stairs comprising 44,645 treads and 24,090 vertical feet, effectively making Pittsburgh the city with the most stairs in the United States. Some of these staircases are legally called streets but only appear on a map, which gives them their appropriate name ‘paper streets’."
--from Paper Streets of Pittsburgh by Anna J. Cawrse
You are looking for a small, clear tupperware at the top of this Paper Street.