The Letu Subtropical Primeval Rain Forest covers an area of 320 mu (213,344 square km). The rain forest plant species number as many as 1,800, 1,700 of which are rare medicine materials, such as eaglewood, Ba Ji Tian and Jin Bu Huan. There are also national first-class protection plant spinulose tree fern in the area. The age-old towering trees in the forest bulge their roots to ground and stretch their crowns to the sky so as to cover all the sky. Innumerable lianas intertwine and climb up from each other, forming vivid pictures of a curled-up dragon on the pillar reaching to the treetops, or ladders and bridges stretching across the valley. The largest liana in this forest is known as the largest liana in China, the stem of which is 52 centimeters wide, and the principal stem is more than 250 meters long. It has more than 2,000 meters of branches climbing on 15 big trees, and the leaves blot out the sky and cover up the earth in its territory, which is truly one of the most wonderful sights in the world.