In the wisdom of the Five Elements in ancient China,the north belongs to Water. It is called Runxia (moistening and descending). Its color is black, and its taste is salty. For people, it corresponds to hearing. Among the Five Constant Virtues, it corresponds to Wisdom. In terms of seasons, it corresponds to winter. Among the stars, it corresponds to the 辰 Star (Chenxing). Its form is the Black Tortoise (Xuanwu).