Sri Lanka is a small tropical island off the southern tip of India. The island nation covers approximately 25,332 square miles (65,610 square kilometers) and is divided ecologically into a dry zone stretching from the north to the southeast and a wet zone in the south, west, and central regions. This contrast in rainfall combined with topographical differences has fostered the development of regional variation in economy and culture. The north-central plains are dotted by the ruins of ancient kingdoms built around man-made lakes. The northern tip of the island is the traditional home to the Sri Lankan Tamils who consider Jaffna, its principal city, their cultural and political center. The dry lowlands of the eastern coast, site of fishing and rice cultivation, are particularly diverse both ethnically and culturally, with Muslims, Tamils, and Sinhalas composing almost equal portions of the population in some areas. The central highlands are famous for tea plantations and, in the southwestern part, gem mines. Kandy, the principal city of this central "Hill Country," was the seat of the last of the indigenous kingdoms and continues to be an important ritual, administrative, and tourist center. The southern coastal lowlands are the site of coconut, rubber, and cinnamon estates, an active fishing industry, and beautiful beaches. Located on the west coast is the island's largest city, Colombo, a hub of international commerce as well as the seat of government administration located on its outskirts in Sri Jayawardenepura.