Longquan is one of the ten most famous swords in ancient China. Also called longyuan 龍淵 [dragon abyss], it is said to be made by the prestigious blacksmiths Ou Yezi 歐冶子 and Gan Jiang 干將 in the Spring and Autumn time (770 BCE-403 BCE), and will manifest the image of abyss for anyone looking at it. Later, longquan is used as a byword for the sword.
