Ma Pi Leng Pass, according to the H’Mong sound, is more accurately written as Ma Pi Leng – also known as Ma Pi Leng or Ma Pi Leng. This pass is famous for its winding roads like a snake wriggling from one mountain to another. The height, ruggedness and length make O Quy Ho pass known as the “king of the Northwest Pass”. The top of O Quy Ho pass is located between the mountains and clouds, also known as the Heaven Gate. In the middle of the pass, it is often cloudy and covered with clouds, at the foot of the pass are scattered villages. When approaching the top of the pass, almost no village can be seen, but only the deep blue sky and majestic mountains seem to blend into one. With a length of more than 20 km, Khau Pha pass is like a dark silk strip crossing the slopes of a highland. Although only 7km long, Cu Mong is considered one of the most dangerous mountain passes in Vietnam. The height of the top of the pass is 245m, the slope is 9%, there are many sharp bends with a small curve radius, the two sides are high mountains. The pass is hidden behind the dark green curtain of Truong Son forest in the west of Quang Binh province. With the bends of the sleeves and the primeval old forest, Da Deo pass is a road that many riders want to challenge. This is the most beautiful pass among the passes on National Highway 3 from Phu Lo to Ta Nung border gate. Coming here, you will see fields of buckwheat flowers in spring and green corn fields in summer. The road of Hai Van pass is winding and zigzagging with majestic mountains on the other side, and the cool blue sea below, forming a magnificent natural picture.