Yesterday, I was sent on an errand to our graphics department on the 10th floor. As I exited the elevator and made my way along the glass wall, I glanced down and noticed a roof garden. Wow! A ROOF GARDEN! Why hadn't anyone told me about this?
This particular roof garden in fake. It is plastic rocks and bushes. There is no public access. It was meant to be viewed from adjacent buildings, particularly the Museum Tower Residential Building rising above the Museum.
Here is a good article.