Virginia consists of three principal physiographic areas: the Atlantic Coastal Plain, or Tidewater; the Piedmont Plateau, in the central section; and the Blue Ridge and Allegheny Mountains of the Appalachian chain, in the west and northwest.
The long, narrow Blue Ridge rises sharply from the piedmont, reaching a maximum elevation of 5,729 ft (1,747 m) at Mt. Rogers, the state's highest point. Between the Blue Ridge and the Allegheny Mountains of the Appalachian chain in the northwest lies the Valley of Virginia, consisting of transverse ridges and six separate valleys. The floors of these valleys ascend in altitude from about 300 ft (90 m) in the northern Shenandoah Valley to 2,400 ft (730 m) in the Powell Valley. The Alleghenies average 3,000 ft (900 m) in height.
The Piedmont, shaped roughly like a triangle, varies in width from 40 mi (64 km) in the far north to 180 mi (290 km) in the extreme south. Altitudes in this region range from about 300 ft (90 m) at the fall line in the east to a maximum of about 1,000 ft (300 m) at the base of the Blue Ridge in the southwest. The Tidewater, which declines gently from the fall line to sea level, is divided by four long peninsulas cut by the state's four principal rivers—the Potomac, Rappahannock, York, and James—and the Chesapeake Bay. On the opposite side of the bay is Virginia's low-lying Eastern Shore, the southern tip of the Delmarva Peninsula. The Tidewater has many excellent harbors, notably the deep Hampton Roads estuary. Also in the southeast lies the Dismal Swamp, a drainage basin that includes Lake Drummond, about 7 mi (11 km) long and 5 mi (8 km) wide near the North Carolina border. Other major lakes in Virginia are Smith Mountain—at 31 sq mi (80 sq km) the largest lake wholly within the state—Claytor, and South Holston. The John H. Kerr Reservoir, covering 76 sq mi (197 sq km), straddles the Virginia–North Carolina line.