1. Delaware Raritan Canal Path: Flat but green escape from urban energy of the city. Access at Cadwalader Park.
2. Washington Crossing State Park (NJ and Pa.) Lots of hiking trails in this state park off of Rt. 29 north of Trenton (Rt. 30 on the Pa. side.) Pennsylvania side has hike up to Bowman's Tower for nice view.
3. Delaware Raritan Canal (South) Newly restored path allows you to hike from Trenton to Bordentown along the former canal (You can take the light rail back). You'll walk through wetlands and wooded areas. About 5 miles in length. Pick up trail at Duck Island part of south Trenton (From Rt. 129 east). Look for gates that block vehicles from entering the trail (Near power lines). You can also start at Riverfront Park and then walk through the industrial area at Duck Island until you come upon the trail (Make left about a quarter mile down road and trail will be on right.)
4. Assunpink Wildlife Refuge: About a 20 minute drive from Trenton. Fields, farms, forests, lakes, and hills bring back a rural landscape typical of areas surrounding Trenton fifty years ago. Several horse trails traverse the area. Hunting allowed but forbidden on Sundays. Usually free of hunters except November thought February. East on Rt. 195. Exit the Imlaystown exit. Head over highway to the north on Imlaystown-Hightstown Rd. and continure to the end of the road.
5. High Rocks (Part of Ralph Stover State Park Tinicum Twp., Pa.) Probably the most dramatic scenery in our area. Includes cliffs and mountain panorama before hike down to the fast moving river. Head north on Rt. 30 from New Hope, Pa. Almost an hour from Trenton.
Directions at: http://www.alltrails.com/trail/us/pennsylvania/high-rocks
6. Baldplate Mountain: Baldplate is the highest point in Mercer County Panoramic view of the Delaware River and surrounding countryside. Miles of hiking though woods, hills, and some fields. Possible to hike from there to Howell Living History Farm and back (Refreshments and programs available at Howell Farm.)
Take Rt. 29 north, Turn right on Fiddlers Creek Rd. (north of WashingtonCrossing Park). Parking area on left.
7. Mercer County Park (East and west):
Numerous trails traverse these parks.
8. Spring Lake (Hamilton-Trenton Marsh)
Nearby from Mott School. Access from South Broad St. at Sewell Ave.
Walk through marshland and wooded trails. Good site to spot wildlife (birds, amphibians, reptiles). Former site of 19th Century amusement park. Still some remnants. Nature center open at times.
9. Delaware Water Gap: Although a good drive from Trenton (About 2 hours), this is the most well known hike in NJ. Mt. Tammany is most travelled trail. It offers great views of the Water Gap from cliffs. It is 3.3 miles with a challenging uphill climb. Expect crowds on a nice weekend day. Other trails are found in this area as well as a connection to the Applachian Trail (A trail that runs most of the U.S. east coast.)
10. Pine Barrens: The Pine Barrens can be intimidating to someone who's not familiar with them. One can imagine getting lost in one of the largest wilderness areas on the east coast. However, there are several well marked trails for hikers. I would suggest starting at these areas: Batsto State Park (Visitor center can assist hikers), Wells River County Park (Visitor Center), and Whitesbog (sand roads, general store open on weekends. Guided hikes.)
Photo source: Photokaz.com