During the Tang Dynasty (618-907), the central government established Yong'an Town in the area, and it was promoted as Yong'an County. This was in order to avoid mistaking it with the Yong'an Mausoleum of the Emperor Taizu in the Song Dynasty (960-1279), the region was named after Xian'an with similar meaning with the former one, Yong'an. The southern part of the city is higher than the north. Lake and river alluvial plains are found in the north-west. Xianning City also has low mountains and hill regions in its center, with medium high mountains lying in its southern part. The city bears a subtropical continental monsoon climate featuring rich rainfall and sunshine, and enjoys four seasons. There are northerly winds in the winter when the weather is dry and cold, while summer is quite the opposite, with the weather being torrid and wet. The best time to visit is Spring and Autumn.