Back in April of last year, I led a tour of Green-Wood for a class of Cooper Union students. At the end of the tour, their instructor, Michael Dorsch, asked me to show them our display of 19th-century vault keys in our offices. I did so and the students were fascinated. In fact, I soon heard from the one of them, Troy Kreiner, who was interested in doing some sort of project with the keys. Click here to see the rest of this post, with images, on the Green-Wood website.