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".