Phu Xai Lai Leng is a mountain of the Annamite Range in Southeast Asia. It is 2720 metres tall and sits on the international border between Laos and Vietnam. It is one of the ultra prominent peaks of Southeast Asia.

Phu Xai Lai Leng is lying on the border between Laos and Vietnam. With a height of 2720 meters, it is the second tallest mountain in Laos. Phu Xai Lai Leng is one of the ultra prominent peaks in Vietnam and Laos, suitable for those who get used to with craggy area. Phu Xai Lai Leng is located on the Vietnamese border and measures in at 2,720 metres. The mountain is mainly composed of granite and is covered with Asian rainforest. The mountain is home to a variety of plant species, including a series of mosses and flowers. The road leading to the top of the mountain is mainly used by tourists seeking exhilarating adventure. Phu Xai Lai Leng offers stunning views to adventurous hikers. The summit provides a bird's-eye view of the entire city covered with forests, waterfalls and other mountains.

The mountain appears like a majestic wall. Over the landmark 422, tourists can see Xieng Khouang on the other side. Also, Exploring Phu Xai Lai Leng is not simply climbing but also learning the cultural life of local residents with an ancient history of over hundred years. Na Ngoi commune is living at the foot of Vietnam with more than 5,000 people, of which H’mong people account for 80%.

Phu Xai Lai Leng is considered the highest mountain in Nghe An province and higher than all other mountains of the Truong Son range. According to the notes of geographers, Phu Xai Lai Leng peak on a 2.711m altitude, stretching from the northwest Nghe An on the border with Laos to Hong Linh mountain in Ha Tinh province.

Phu Xai Lai Leng appears like a bulky majestic wall. Over the landmark 422, on the other side is Xieng Khouang Province, Laos, at the foot of Phu Xai Lai Leng on Vietnam territory is Na Ngoi commune with more than 5,000 people, H'mong people account for 80%. Phu Xai Lai Leng in the H'mong language means "seen everywhere" referring to the lofty height of the mountain.

Phu Xai Lai Leng is also the station of the military border forces. To discover the high peak, people have to register at the Na Ngoi border station, the officers, border guards here who are willing to help. This border region is characterized by subregion climate, midday is burning hot, afternoon thunderstorms and lightning, evening is freezing cold.

Explore Phu Xai Lai Leng is not simply climb a high mountain but also learn the cultural life of local residents. At the foot of Phu Xai Lai Leng is 17 H'mong villages, in which Buoc Mu is typical with an ancient history of over hundred years.