This part of northern Virginia has two first-rate hiking, biking, and running trails. A 17-mile paved trail starts at Memorial Bridge and borders the George Washington Memorial Parkway south to Mount Vernon, passing through Old Town on the way.

Beginning in the Shirlington area, on I-395 in neighboring Arlington, the Washington & Old Dominion (W&OD) Trail follows Four-Mile Run Drive and Glencarlyn Park northwest to an old railroad bed, which then proceeds 45 miles through Leesburg to Purcellville. Big Wheel Bikes, 2 Prince St., at The Strand (tel. 703/739-2300), rents a wide range of bikes beginning at $5 an hour. Open Monday to Friday 11am to 7pm, Saturday 10am to 6pm, Sunday 11am to 5pm.

You can learn to paddle, explore local waters, or go on guided trips with Atlantic Kayak, 1201 N. Royal St. (tel. 800/297-0066 or 703/838-9072). Call or check their website for classes, demonstrations, and day trips along the Potomac River and as far away as the Eastern Shore.