North Carolina is a state in the Southeastern United States. The state borders South Carolina and Georgia to the south,Tennessee to the west and Virginia to the north. North Carolina is the 28th most extensive and the 10th most populous of the 50 United States. North Carolina is known as the Tar Heel State and the Old North State. North Carolina is composed of 100 counties. Its capital is Raleigh, and its largest city is Charlotte. In the past five decades, North Carolina's economy has undergone a transition from heavy reliance upon tobacco and furniture making to a more diversified economy with engineering, biotechnology, and finance sectors. North Carolina has a wide range of elevations, from sea level on the coast to 6,684 feet (2,037 m) at Mount Mitchell, the highest point in the Eastern US. The climate of the coastal plains is strongly influenced by the Atlantic Ocean. Most of the state falls in the humid subtropical climate zone. More than 300 miles (500 km) from the coast, the western, mountainous part of the state has a subtropical highland climate.