Lang Son terrain is largely low hills. The average height is 252m over the sea level. The lowest point is 20m from the south of Huu Lung district, and the maximum point is Mau Son Mountain with 1541 m large. Mau Son is located about 30km from Lang Son city. Amazing view by mountains, sometimes has snow in winter. The most attractive in Lang son is Bac Son valley. These mountains, along with the valley’s paddy fields. Bac son become one of the most famous tourist site in Lang son for visitors. These are many activities in Bac son like. trekking, photograph, homestay. you may interest tours to Bac Son here. Lang Son climate features the tropical monsoon climate of the North Vietnam, the average temperature is from 17 to 22°, C, the temperature of the coldest month can fall down 5°, C or below 0°, C. The yearly average moisture of Lang Son is from 80 to 85%, lower compared to other regions in the country. Lang Son situates in the northeast region, therefore the average rainfall is 1200 – 1600 mm. The only place with the rainfall more than 1600 mm is Mau Son inland region. Na Sam and Dong Dang Lang Son – the arid regions of the North.