The region was separated from China proper by the Inner Willow Palisade, a ditch and embankment planted with willows intended to restrict the movement of the Han Chinese into Manchuria during the Qing dynasty, as the area was off-limits to the Han until the Qing started colonizing the area with them later on in the dynasty's rule. This movement of the Han Chinese to Manchuria is called Chuang Guandong. The Manchu area was still separated from modern-day Inner Mongolia by the Outer Willow Palisade, which kept the Manchu and the Mongols separate.