For decades, the 750-acre woodland known both as the Horace Williams Tract and Carolina North, was the unofficial playground of folks from Chapel Hill and Carrboro. About 10 years ago, it started to become a more official playground. In part, the change was necessitated by the unofficial trail network's increasing use by mountain bikers and a desire by the University of North Carolina at Chapel Hill, which owns the tract, to minimize user impact. In return for "official" access, local mountain bikers were invited to help build and maintain the trails. The network has since become the better for it. Carolina North is one place where hikers, runners and bikers recreate together in relative piece. In part, that's because the mountain bikers are more attracted to the twisty-turny singletrack trails that best test their skills. Trail runners, on the other hand, gravitate to the forest roads that offer straighter passage with some nice, rolling challenge. From the main trailhead off Martin Luther King Jr. Boulevard there's a primary loop, the 2-mile The Pumpkin, and the out-and-back The Vine, which will add close to another 2 miles. Cross Seawell School Road near the elementary school that shares the name and you'll find another 2+ miles of doubletrack. You can also run the singletrack favored by the mountain bikers, which is incorporated into both the 7K and 15K versions of The Philosopher's Way annual trail run. Check out the courses of both runs here. http://www.trailheads.org/pwtr/coursemaps.html More info here. Maps here. Getting there from downtown Chapel Hill here.