Taijitu the Tibetan designs have three or four swirls (representing the Three Jewels or the Four Noble Truths, i.e. as a triskele and a tetraskelion design), Lai Zhide's taijitu has two swirls, terminating in a central circle. The Ming-era design of the taijitu of two interlocking spirals has been reported as "yin-yang symbol" in the first half of the 20th century. The flag of South Korea, originally introduced as the flag of Joseon era Korea in 1882, shows this symbol in red and blue. This was a modernisation of the older (early 19th century) form of the Bat Quai Do used
Yin and yang word "yang" "sunny side" and a few contain "yin" "shady side". In China, as elsewhere in the Northern Hemisphere, sunlight comes predominantly from the south, and thus the south face of a mountain or the north bank of a river will receive more direct sunlight than the opposite side. "Yang" refers to the "south side of a hill" in Hengyang 衡陽, which is south of Mount Heng 衡山 in Hunan province, and to the "north bank of a river" in Luoyang 洛陽, which is located north of the Luo River 洛河 in Henan. Similarly, "yin" refers to "north side of