You can walk on the road that is closed to vehicles in South Mountain Reservation. Park near the dog park.
It is just over 2 miles out and back.
If you are willing to push the one hour limit, Princeton University is a great campus to walk around and their new art museum is free. Then you can have a meal downtown for the full experience.

My wife and I enjoy walking a few miles - - gets some fresh air, and (as seniors) its nice to just "move". I realize there are many hiking trails all around us, but we much prefer walking on concrete, sidewalks. We've walked around McCloones a zillion times and we truely enjoy it there. Aside from just walking randomly throughout our neighborhoods, does anyone know of nice, clean, safe walking paths withinan hours drive or so?
Years ago, we went walking on a nice path through the mountains, I believe in Hamburg, NJ. I also recall a lovely walking path near Providence, NJ. However, we both forgot specifically where these are (ok/ok maybe its time for Prevagen!)
Does anyone have any recommendations?