Dong Dang is a small town in Lang Son province whose name is associated with the legendary tale about To Thi in Vietnamese literature. It became a key fortress in the nation’s defense of the northern border during the war in 1979.

Forty years ago, Lang Son was one of the strongest fronts in the war to protect the nation’s northern border. Dong Dang was the most important fortress in town with a system of tunnels built inside the mountain, on top of which were solid blockhouses. The fortress could accommodate hundreds of people.

When entering the gateway town of Lang Son, the Chinese troops claimed to “have breakfast in Dong Dang, and dinner in Hanoi the same day”.

But for five days, the enemy was unable to penetrate the fortress which was protected by the soldiers of Company 42, Regimen 4, Division 3 (Golden Star division) and police armed forces (border soldiers now).

On February 22, 1979, the Chinese troops used explosives to collapse the main entrance gate of the fortress, dropped grenades into air holes and poured gas to set a fire, killing many wounded soldiers and civilians.

The resilient stand against Chinese troops by the soldiers at Dong Dang stronghold gave more time for the country to prepare to fight back.

By Viet Linh