Located in the Southeastern United States, South Carolina is composed of five geographic areas, whose boundaries roughly parallel the Atlantic coastline. It contains many salt marshes and estuaries, as well as natural ports such as Georgetown and Charleston. South Carolina has a humid subtropical climate, although high elevation areas in the “Upstate” or “Upcountry” area have less subtropical characteristics than areas on the Atlantic coastline. The Piedmont (Upstate) region contains the roots of an ancient, eroded mountain chain. It is generally hilly, with thin, stony clay soils, and contains few areas suitable for farming. Tourism is quite popular in South Carolina, with many beaches and state parks, open for visitors. Some resorts also offer spa treatments, while day spa centers can be found in larger cities.