Mercer County Park is the largest park in the Trenton area and a good spot for a destination run. Located 8 miles east of Trenton, this 2500-acre park features a nice variety of terrain, including fields, Mercer Lake, and some wooded sections. Overall, there are 6-7 miles of fairly flat paths. For running, the best bets are the 3.3 mile paved bike trail and the 2.4 mile bike path that follow the main road in the park. This park map shows all the trails and distances.
There are also numerous other recreation facilities in the park.