Manassas National Battlefield Park: Leashed dogs are welcome throughout the 5,100 acres of former Civil War battlefields, less than an hour from DC, and park rangers lead tours. One warning: Dogs scared of loud noises should steer clear in the summer, when cannon demonstrations take place. $3 admission. 6511 Sudley Road, Manassas; 703-361-1339.
Mount Vernon: Dogs are welcome to explore George Washington’s 500-acre estate on the banks of the Potomac. They’re even allowed through some indoor areas in order to access and exit the grounds. Admission $17, annual pass $30. 3200 Mount Vernon Memorial Hwy., Mount Vernon; 703-780-2000.
National Arboretum: DC’s hiking-in-the-city gem is a 446-acre living museum of trees, shrubs, and herbaceous plants that welcomes pets. Visitors can stick to the nine miles of paved roads or choose rugged trails through woods. Free admission and parking. 3501 New York Ave., NE; 202-245-2726.
Quiet Waters Park: A less rustic setting to hike in than some, Quiet Waters has 340 acres of parkland and six miles of paved trails. Some routes wind through forests and fields; others offer scenic views of the South River and Harness Creek. Afterward, dogs can stop by the self-service baths at Bark ’n’ Bean (barknbean.com) outside the park. Admission $3 per car. 600 Quiet Waters Park Road, Annapolis.
Scott’s Run Nature Preserve: Scott’s Run, just outside the Beltway, offers 300-plus acres of dog-friendly trails. The wide River and Woodland trails are good for running with dogs. More challenging hikes wind down rocky cliffs. Free admission and parking. 7400 Georgetown Pike, McLean; 703-759-9018.
State Arboretum of Virginia at Blandy Experimental Farm: While humans learn about native plants, dogs can run off-leash—yes, off-leash— through 170 acres. One exception: They must be leashed within 200 feet of buildings. Free admission and parking. 400 Blandy Farm Lane, Boyce; 540-837-1758.