Anuradhapura attained its highest magnificence about the commencement of the Christian era. In its prime it ranked beside Nineveh and Babylon in its colossal proportions—its four walls, each 16 miles (26 km) long, enclosing an area of 256 square miles (663 km²) —in the number of its inhabitants, and the splendour of its shrines and public edifices. The city also had some of the most complex irrigation systems of the ancient world, situated in the dry zone of the country the administration built many tanks to irrigate the land. Most of these tanks still survive. To date, it is believed that some of these tanks are the oldest surviving reservoirs in the world today.
