The Caribbean region is a region consisting of the Caribbean Sea, its islands, and the surrounding coastlines. The region lies southeast of the Gulf of Mexico and mainland North America, east of Central America, and north of South America. The region lies largely on the Caribbean Plate, and includes more than 700 islands, islets, reefs, and arcs. These islands generally form island arcs that define the eastern and northern limits of the Caribbean Sea. The Caribbean islands, consisting of the Greater Antilles in the north and the Lesser Antilles in the south and east, are part of the somewhat larger West Indies group, which also includes the Lucayan Archipelago north of the Greater Antilles and the Caribbean Sea. In a broader sense, the mainland countries of Belize, Guyana, Suriname, and French Guiana are often included because of their political and cultural ties to the region. In geopolitical terms, the Caribbean islands are usually considered a subregion of North America, and are organized into 30 territories including sovereign states, overseas departments, and dependencies.