Sean from NYC Exposed sent in a link to this gallery of subway tunnel shots-- along with a note: "I revisited 2nd ave." Could this be the fabled section of the Second Avenue line that actually got built? If anyone is going to get down there, it's NYC Exposed-- they've got one of the best collections of subway/tunnel pictures we've seen so far.
Related: Curbed notes that Property Shark has added the Second Avenue subway line to its maps-- seems a bit early for that! Cityspecific goes up to 191st Street on the 1 Train, and checks out the three block long tunnel that connects the station to Broadway. Spooky!