The hanging coffin is a funerary custom practised among those ethnic minority groups in ancient southern China that were primarily distributed in areas in the middle and lower reaches of the Yangtze River and in most of the regions south the Yangtze River. Hanging coffins on the cliffs of Mount Wuyi are the oldest among all types of hanging coffins ever found, and are suspected to be from the Xia and Shang dynasties 3,000-plus years ago. It is speculated that the boat-shaped coffin used as a hanging coffin was probably initially an implement used by a people living on the river, lake or sea; the boat was used as a coffin after a member of the people died, and this is psychologically natural. The Danxia landform at Mount Wuyi provides ideal cliff caves for the cliff burial custom. As dry cliffs helped preserve the remains of the dead in the moist climate of southern China, the ancient Chinese placed the boat-shaped coffin high up on a cliff using great wisdom and advanced mechanical tools.