Anuradhapura is Sri Lanka's first capital, a potent symbol of Sinhalese power, and the most extensive and important of Sri Lanka's ancient cities. For over 1000 years, Sinhalese kings, and occasional South Indian interlopers, ruled from the Palace of Anuradhapura and its size and the length of its history, and equally the length of time since its downfall, make it more difficult to comprehend. Founded in the 4th century BC, it was the capital of the Anuradhapura Kingdom 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. The great building era was when vast monastery complexes and some of the tallest buildings in the ancient world were built.