Dayan, commonly called the Old Town of Lijiang is the historical center of Lijiang City, in Yunnan, China. It is a UNESCO World Heritage Site. The town has a history going back more than 1,000 years and was once a confluence for trade along the "Old Tea Horse Caravan Trail". The Dayan Old town is famous for its orderly system of waterways and bridges, …Dayan, commonly called the Old Town of Lijiang is the historical center of Lijiang City, in Yunnan, China. It is a UNESCO World Heritage Site. The town has a history going back more than 1,000 years and was once a confluence for trade along the "Old Tea Horse Caravan Trail". The Dayan Old town is famous for its orderly system of waterways and bridges, a system fast becoming but a memory as the underground water table drops, probably due to over-building in the suburban areas.