Anuradhapura is a major city in Sri Lanka. Anuradhapura is one of the ancient capitals of Sri Lanka famous for its well-preserved ruins of ancient Sri Lankan civilization. The city, now a UNESCO World Heritage Site was the center of Theravada Buddhism for many centuries. It is believed that from the 4th century BC, it was the capital of the Sinhalese until the beginning of the 11th century AD. During this period it remained one of the most stable and durable centers of political power and urban life in South Asia. The ancient city, considered sacred to the Buddhist world, is today surrounded by monasteries covering an area of over sixteen square miles (40 km²).