As a special national relic site, the citadel has gone down into national history as a symbol of bravery after local military units and people fought for 81 days against enemy troops, from June 28 to September 16, 1972.
This contributed to the success of the Paris talks and the 1975 Spring Campaign which ultimately brought about the liberation of the southern region and national re-unification.
An estimated 328,000 tonnes of bombs were dropped on the old citadel and a small town of some 10,000 houses around it. By the time the fighting ended, the town was almost leveled. No houses remained intact.
The last day of the fighting (September 16) was then designated as the death anniversary of all the martyrs./.