Board a Manhattan-bound Q or B train from DeKalb Avenue in Brooklyn (or on weekends, currently due to constructions, the R train runs on this track as well) and look out the right side just before the train emerges out of the tunnel onto Manhattan Bridge.
You'll see a unique and playful piece of urban art: an underground zoetrope ("a device that produces an illusion of action from a rapid succession of static pictures"). This is one of my favorite "hidden" treasures of New York City.
The first time I noticed Masstransiscope, I thought it was just graffiti, but I was puzzled by why it was so brightly lit. And then when it registered that this "graffiti" was "alive" and moving with a specific intent, my brain exploded. I consider it a real treat that this is a frequent sighting in my regular commute and it never gets old. Vast majority of the people on the train never notice, but occasionally after the train passes this mass-transit zoetrope, I'll make eye-contact with a stranger whose eyes too were caught by Masstransiscope and we smile as if we just shared a wonderful secret. The reaction of little kids to it is particularly awesome. They respond to it like Christmas. "Mommmmm! Looooook! It's moving!!!!"
I'm almost hesitant to share a video of Brandt's underground work because I don't want to spoil it for you. I highly recommend everyone take this train to see it in person. That said, for my friends and readers who don't live in New York City, here it is:
[youtube=http://www.youtube.com/watch?v=3IwVD5efXz0&fmt=18]