Changbai Mountain Tianchi is a dormant volcano. The crater is filled with water. The water in the summer is more blue than the sky. It is surrounded by 16 peaks. There is only a narrow pool of water overflowing between Tianchaofeng and Longmen Peak. It is the source of the Songhua River. Lvyuantan is named after Yuehua Yin and Tanshui. The Luyuantan Waterfall flows down directly, with a maximum drop of 26 meters. The waterfall falls on the boulder and then gradually flows into the deep pool. Every time the fog rises, the water on the pool is filled with water, and it is integrated with the mountains and the birch and the ancient stone. It is beautiful, just like the fairyland on earth. * It is said that in the "Tomb Notes", the world is guarded by Zhang Qiling, and the bronze door is in the mountain behind the waterfall.