Virginia officially the
Commonwealth of Virginia, is a U.S. state located in the South Atlantic region of the United States. Virginia has a total area of 42,774.2 square miles (110,784.7 km
2), including 3,180.13 square miles (8,236.5 km
2) of water, making it the 35th-
largest state by area. Virginia is bordered by Maryland and Washington, D.C. to the north and east; by the Atlantic Ocean to the east; by North Carolina and Tennessee to the south; by Kentucky to the west; and by West Virginia to the north and west. Virginia's boundary with Maryland and Washington, D.C. extends to the low-water mark of the south shore of the Potomac River. The southern border is defined as the
36° 30′ parallel north, though surveyor error led to deviations of as much as three
arcminutes.
The Chesapeake Bay separates the contiguous portion of the Commonwealth from the two-county peninsula of Virginia's Eastern Shore. The bay was formed following a meteoroid impact crater during the Eocene. Many of
Virginia's rivers flow into the Chesapeake Bay, including the Potomac, Rappahannock, York, and James, which create three peninsulas in the bay. Geographically and geologically, Virginia is divided into five regions from east to west:
Tidewater, Piedmont, Blue Ridge Mountains, Ridge and Valley, and Cumberland Plateau.
The Tidewater is a coastal plain between the Atlantic coast and the fall line. It includes the Eastern Shore and major estuaries of Chesapeake Bay. The Piedmont is a series of sedimentary and igneous rock-based foothills east of the mountains which were formed in the Mesozoic. The region, known for its heavy clay soil, includes the Southwest Mountains. The Blue Ridge Mountains are a physiographic province of the chain of Appalachian Mountains with the highest points in the state, the tallest being Mount Rogers at 5,729 feet (1,746 m). The Ridge and Valley region is west of the mountains, and includes the Great Appalachian Valley. The region is carbonate rock based, and includes Massanutten Mountain. The Cumberland Plateau and the Cumberland Mountains are in the south-west corner of Virginia, below the Allegheny Plateau. In this region, rivers flow northwest, with a dendritic drainage system, into the Ohio River basin.
The state's carbonate rock is filled with more than 4,000 caves, ten of which are open for tourism. The Virginia seismic zone has not had a history of regular earthquake activity. Earthquakes are rarely above 4.5 in magnitude because Virginia is located away from the edges of the North American Plate. The largest earthquake, at an estimated 5.9 magnitude, was in 1897 near Blacksburg. A 5.8 magnitude earthquake struck central Virginia on August 23, 2011, near Mineral. The earthquake was reportedly felt as far away as Toronto, Canada, Atlanta, Georgia and Florida. Coal mining takes place in the three mountainous regions at 40 distinct coal beds near Mesozoic basins. Other resources such as slate, kyanite, sand, and gravel are mined, with an annual value of nearly $2 billion as of 2006[update].