Because the picture pretty much already gives it away, the only clue is I was on the southside when I took this. Where was I?
UPDATE: Within 10 minutes of posting this my friend Lisa posted the answer on Facebook: It is embedded in the sidewalk in front of the old Bethlehem Steel headquarters on 3rd Street. Sorry it only took me 6 weeks or so to update this!
AH! No idea this time. I’ve totally never seen this before. Will be interested to find out!