Princeton University's beautiful and historic campus is an open one, so anyone can enter the grounds, take pictures, and soak-in the atmosphere.
When you go, try to make time to tour the university's art museum, which is a gem, and is free. And, if
Nassau Hall (the original building) is open, that is also worth a look. Nassau Hall was actually the location of the new US government for a brief time during the American Revolution, so it is steeped in history.
The
Firestone Library is another building that you should see, and the university's chapel--adjacent to the library--is a cool and beautiful refuge on a hot day. If you are lucky, the choir might be rehearsing while you are there.
Street parking can be a bit...tight...so I advise using the municipal parking garage, which located one block west of Nassau Street, and which is relatively inexpensive. The campus is only a very short walk up Witherspoon Street from the parking garage, and on the way to the campus you can avail yourself of a cup of coffee at
Small World, an independent coffee roasting company that brews extremely good coffee.
Enjoy!