The bagua (Chinese: 八卦; pinyin: bā guà; Wade–Giles: pa kua; lit. 'eight symbols') is a fundamental philosophical concept in ancient China. It is an octagonal diagram with one trigram on each side. The concept of bagua is applied not only to Chinese Taoist thought and the I Ching, but is also used in other domains of Chinese culture, such as fengshui, martial arts, navigation, and so on.