According to Book of History·Yao, the only temple of Xihe is at Dongshe at the foot of today's Mount Yun. According to the legend, four people including Xihe were in the four places, Dongshe, Zhongshe, Xishe and Gaoju, at the foot of Mount Yun. Taking Yuandazhen, the highest peak of Mount Yun, as Beiding Gaoju, they observed the Big Dipper and determined the four seasons of spring, summer, autumn and winter as well as vernal equinox, autumnal equinox, summer solstice and winter Solstice, in accordance with the changing direction of the handle of the Big Dipper, the length of day and night and the replacement of birds and beasts' feathers. Then, Houji, farming official of Yao, instructed the people to farm according to farming seasons.
After years of observation, they developed the summer calendar, which not only accurately determined vernal equinox, autumnal equinox, summer solstice and winter Solstice, but also divided a year into 366 days.
Now, the temple and the tomb of Xihe lie at the foot of the mountain to the south of Mount Yun. Xihe became the founder of the ancient calendar, and Mount Yun became the birthplace of vernal equinox, autumnal equinox, summer solstice and winter Solstice as well as the 24 solar terms.
