Raleigh Durham Airport is one of the few in the United States to offer a dedication place to watch aircraft movements without being hassled by security or police personnel. This is the Observation Park (which has recently been refurbished).
However, there is a lesser known SECOND official location at the airport which is also good for watching and spotting aircraft.
The General Aviation Terminal is situated to the north east of the passenger terminal complexes, adjacent to the end of runway 23L. It offers a balcony on the second floor which overlooks the GA ramp and runway, and is good for photography of aircraft close by.
It is also possible to see aircraft using the main runway behind, and also taxiing to and from the main terminals. The main draw of the location is seeing the various light and executive aircraft parked at the terminal which wouldn’t usually be seen from the main terminals.
Parking is free at the GA Terminal, and there’s a cafe for you to use.