The Outer Banks (frequently abbreviated OBX) are a string of barrier islands and spits off the coast of North Carolina and southeastern Virginia, on the east coast of the United States. They line most of the North Carolina coastline, separating Currituck Sound, Albemarle Sound, and Pamlico Sound from the Atlantic Ocean. A major tourist destination, the Outer Banks are known for their wide expanse of open beachfront and the Cape Hatteras National Seashore. The seashore and surrounding ecosystem are important biodiversity zones, including beach grasses and shrubland that help maintain the form of the land.