Dragon Hole, also known as Yongle Blue Hole named after the third Ming emperor, is the deepest known blue hole in the world at 300.89 metres (987.2 ft) deep. It is located about 25 kilometres (16 mi) south of Discovery Reef in the Paracel Islands. Blue holes generate a distinctive blue colour when seen from above. They are characteristically only dozens of metres deep. The local fishermen call it the "eye" of the South China Sea, and according to legend it is where the Monkey King, depicted in the novel Journey to the West, found his golden cudgel.