Pha Din Pass is approximately 32km long, connecting the provinces of Dien Bien and Son La, with its highest point reaching 1,648m above sea level. The name Pha Din originates from the Thai language, "Phạ Đin," where "Phạ" means sky and "Đin" means earth, implying the place where heaven and earth meet. Due to its unique location and rugged terrain, Pha Din Pass is renowned as one of the "Four Great Mountain Passes of Northwest Vietnam."

During the Dien Bien Phu Campaign in 1954, Pha Din Pass was a vital supply route for weapons, ammunition, and food, with thousands of people carrying ammunition and rice passing through daily. It was also the marching route for infantry and artillery forces advancing towards the Dien Bien Phu front. The pass, stretching for tens of kilometers, winding and undulating, was frequently targeted and bombed by French aircraft, resulting in the destruction of many cars, trucks, and rice carts after bombing raids. Pha Din Pass was the most arduous starting point of the arduous journey of the Dien Bien Phu soldiers who hauled artillery by human strength. From here, they traversed many high passes, steep slopes, deep ravines, and high mountains to deliver the cannons to their battle positions, where artillery shells left the barrels, aiming for the strongholds of Him Lam, Doc Lap, Ban Keo… With its special historical value linked to the courage and determination to fight and win of our army and people, Pha Din Pass has been classified as a National Historical Monument.

Today, Pha Din Pass has been renovated, its slope reduced, and the road widened, facilitating traffic while still preserving its majestic beauty. The winding roads amidst the vast mountains and forests, the floating sea of ​​clouds, and the fresh climate create a special attraction for tourists. Along the pass, attractions and experiences have been developed such as Pha Din Pass and Pha Din Top, where visitors can stop to admire the scenery, learn about history, and capture memorable moments. Pha Din Pass is not only an important transportation route but also a typical historical, cultural, and tourism symbol of the Northwest region.