The highlight for me was Grand Central Terminal being the train fan that I am. Grand Central Terminal is the end of a line (thus a terminus) thus it's not a station like Penn Street Station. These days long distance trains don't even come to Grand Central Terminal for exactly that reason and go through Penn Street Station instead. Still Grand Central is one of the busiest train stations in the world with plenty of Subway and local trains using it. It's also one of the most beautiful stations in the world. Thankfully preservationists (and Jacqueline Onassis) were able to keep the owners from tearing it down like they did the original amazing Penn Street Station.