負離子空氣凈化器，在此遊覽感覺特別精神，到了中午也沒有睡意，這個一定是負離子的作用吧！這個是遊覽北坡景區的最後一個小景點。

地下森林是火山口原始森林，林木高低錯落，蔚然深秀。徒步約1.5公里，才能達到地下森林。穿行林間，草木幽香，綠秀繁陰，視線拉近又推遠，一次漫長的散步，怎麼都走不出綠色的目光。高濃度的負離子追逐着，湧進身體，沁人心脾，山林之樂，愉悅至極。林子里的一切都如此的原生態，我們看到了樹木的一生輪迴，有欣欣向榮而生的，有倒下化身為泥土的，有的樹連根倒下，粗壯的根系彷彿“權力的遊戲”中的帝王寶座

屬於長白山北坡景區內的一個景點，一般都是安排最後遊玩，因為在最外面，遊玩結束后一般就坐景區環保車出去了，裏面是長白山原始的森林樹木，空氣質量非常好，一條木棧道一直通到谷底的松花江發源地，大概來回要三公里路，慢慢走就還好。

Valley bottom forest sea, also known as underground forest, is the most beautiful primitive forest scenic spot in Changbai Mountain. This place is a valley forest Sea formed by the subsidence of volcanic eruption, which can not be seen anywhere else. The route of the scenic spot is circular, 3 kilometers in length, which indicates that 80 minutes can be finished, 40-60 minutes can be finished quickly, and 60 meters can be descended and climbed up and down. Take care of the needs of the elderly and children. The scenic spot is full of primitive forest scenery, everywhere towering, magic, essence in the middle of the viewing platform, known as step by step across the Songhua River, full of broken-walled forest sea, like curiosity tourists suggest not to let go. In addition, this can be used as the last scenic spot on the North slope. After the tour, you can go directly to the Mountain Gate by car, not far from it.

The forest is secluded and ancient. Pine needles, moss, dead branches, pine needles and moss are often trapped under the crisscross rock cracks, which can not be pulled out carelessly. The more and more withered trees can be seen everywhere, some hanging upside down on the top of the hill as bare as claws, some standing on rooted cliffs as early as the beginning, some old and decadent fences, and others want to fall down and not lean on it trees... However, around the dead wood, thousands of trees are growing, and the endless green is beyond our control.

Valley bottom forest is located in the scenic area of the northern slope of Changbai Mountain. The north side of Dongtian Falls is the lowest elevation scenic spot of Changbai Mountain. Because of orogeny or volcanic activity, large area of strata collapsed, forming a huge valley, making the whole forest sink into the valley bottom. The ancient trees at the bottom of the valley are towering, and the trees are divided into three layers. The boulders are scattered in different places. They are in the deep of the valley, as if they were swimming in the green ocean. Wooden trestle road is very flat, not tired of traveling in the valley forest, the negative oxygen ion content is very high. All kinds of trees, flowers and plants, as well as dead trees, are very similar to animals. It's worth seeing.