This beautiful building has 28 floors of office space, but it does not have the cache. The container is hidden in a public area near the Cira Centre.
The easiest way to reach the cache is from 30th Street Train Station. Take the escalator near the Regional Rail section to the pedestrian walkway over Arch Street. You will then walk through an elevated portion of the Cira Centre lobby. You do not need to take the escalator down to the lower part of the lobby. Continue walking out of the lobby, and go find the cache.
You will get an up close look at the Cira Centre, and a nice view of Center City.