Introduction to the Pine Forest Grassland: Located at the top of Tianhe Mountain, the pine forest covers an area of ​​more than 10,000 acres. The lush green pine trees, herds of cattle and sheep, are better than the scenery outside the Great Wall. To the northeast, there is a flat land on the top of the mountain, with green grass stretching as far as the eye can see. It is quite a scene outside the Great Wall, like "cattle and sheep can be seen in the wind-blown grass".