Carvins Cove in Roanoke, VA has lots to offer the trail runner looking for challenging terrain near an urban area. The Cove is a city owned watershed area with some 30 to 40 miles of trails, many of them singletrack. The trails range in difficulty from rolling dirt roads to serious singletrack climbs and descents.
Maps of the trails are available at East Coasters Bicycle Shop in Roanoke, as is advice on loops and terrain. Although the area is posted with some 100 "No Trespassing" signs, use of the trails is allowed, and even encouraged.