Steps - Pittsburgh

There are several old and/or abandoned public staircases in Pittsburgh.

(Oakland) Bohem (formerly Blaine) Street steps: These went from the Monongahela River side of Second Avenue up to Bohem Street. On the way, they crossed over Second Avenue, the Eliza Furnace Trail, and the Parkway East via footbridges. See descriptions and photos here and here, photos here and here, and descriptions here, here and here.
(Hazelwood) Noah Street steps: These steps, like the Bohem Steps, went from the former J&L steel mill (now Hazelwood Green) all the way up the hillside. They started on the land side of Second Avenue, next to the railroad tracks, and went all the way up to Noah Street in Hazelwood. On the way, they crossed over the train tracks and Irvine Street on footbridges. See here, towards the end of the post here, and photos of the remaining steps here.
(Hazelwood) From Steele Court at Kilbourne Street, to Nordica Street at Ampere Street. See here and here.
(Oakland) Juno Street to Boulevard of the Allies at Parkview Avenue
(Greenfield) Magee Playground to Monteiro Street
(Larimer) Negley Run Boulevard to Pace Way at Lenora Street, near the Meadow Street Bridge These. Mentioned here (pdf), photo here.
(Westwood) McCartney Street to Noblestown Road