As a young boy I recall visiting Pennsylvania station. The first half block was a beautiful stone structure but the other half block was a high glass ceiling atrium where the steps to the tracks were. There was also a bus depot on the 8th Ave side. You would enter and go up the steps by the Greek columns on 7th Ave walk through some nice corridors/ halls and arrive in the massive glass ceiling area. It was a sight to behold and it could never be duplicated. It should have never been torn down.
The good news is that Monihan station being built in the old Farley Post office building was designed by the same architectural firm and the exterior will look a lot like old Pennsylvania Station.