Halin or Halingyi ( ), located in the Mu valley, one of the largest irrigated regions of precolonial Burma, is the northernmost Pyu city so far discovered. The earliest artefacts of Halin—city's wooden gates—are radiocarbon dated to 70 CE. The city was rectangular but with curved corners, and brick-walled. Excavated walls are approximately long on the north–south axis and on the east–west. At 664 hectares, the city was nearly twice the size of Beikthano. It has four main gates at the cardinal points, and a total of 12 gates, based on the zodiac. A river or canal ran through the city. Traces of a moat exist on all sides except the south, where it was probably not needed, as land was dammed there to create reservoirs.