The closest place to camp near Princeton is Washington Crossing State Park along the Delaware River in Titusville, NJ.
The Mountain Lakes Open Space Area, a “central park” in Princeton, consists of some 400 acres just north of the center of town, most of it open to the public. It has a wide variety of hiking trails- and two biking trails – some connecting to other trails outside of the area described here. Along with views of Tusculum, the estate built by John Witherspoon, and historic Coventry Farm, it features a great variety of open fields, several small streams and lakes, old stone walls, boulder fields, and old growth pine and hardwood forests. The area is divided into five sections: The Billy Johnson Mountain Lakes Preserve, including the Mountain Lakes House; Mountain Lakes North; John Witherspoon Woods; the Tusculum fields; and Community Park North. Most of the remainder of Tusculum, to the east, and Coventry Farm, to the west, is private open space.
The Mercer Country Bikeability Web Site provides detailed trail maps raking the best roads for biking throughout Mercer County.
The 70-mile Delaware and Raritan Canal State Park is one of central New Jersey's most popular recreational corridors for canoeing, jogging, hiking, bicycling, fishing and horseback riding. The canal and the park are part of the National Recreation Trail System. This linear park is also a valuable wildlife corridor connecting fields and forests. The D&R Canal parallels Lake Carnegie and provides easy access from campus for walking, running, and biking both north and south.