Along with thousands of others, teenager Linh camped out overnight to watch Wednesday's military parade marking 50 years since the metropolis, now called Ho Chi Minh City, fell to communist forces to end two decades of conflict.

Communist Vietnam's tightly-controlled state media has pumped out a barrage of positive messaging about the anniversary.

But flag-waving youngsters on the streets of Ho Chi Minh City told AFP that it was TikTok and Instagram posts about preparations for the parade of red-bannered floats and goose-stepping soldiers in recent weeks that had fired their enthusiasm.

Linh, 17, admitted she knew little about the conflict, but was part of a wave of young people with no direct connection to the war who wanted to experience the spectacle.

The event made her "feel quite proud to be Vietnamese", she told AFP.

"We are grateful for what the veterans did for us, for the country, pulling us out of war," said Linh, who had travelled from the capital Hanoi to watch the parade.

"Even if we hate history lessons at school, we can learn so many things from this event that the teachers have tried again and again to tell us."

- 'Great fun' -

Communist North Vietnam's victory over the US-backed South culminated in tanks crashing through the gates of the presidential palace.

The defeat for its Cold War ally, and the chaotic scenes of helicopters desperately evacuating staff from the US embassy roof, marked a painful and humiliating blow to Washington's prestige.

Vietnam's Communist Party has huge sway over education and children are taught about the country's victories in schools nationwide.

The party also exercises complete control of the media in Vietnam, a one-party state.

"There is a non-stop barrage of propaganda about this (anniversary)," Zach Abuza, a professor at the National War College in Washington, told AFP.

But many young people said it was pictures on social media that had got them excited.

"Vietnam doesn't really have many outward showy expressions of military strength," said Vu Minh Hoang from the Fulbright University Vietnam.

"I think most people are surprised or excited by it," said Hoang, a professor of history and Vietnam studies.

"They like to think that Vietnam has a strong military that can defend itself."

Dang Nguyen Tuan Minh, a 21-year-old student, scouted a spot to sit and wait for the parade on Tuesday evening.

"We all had great fun, staying the night together on the pavement like this," he said. "The vibe was so great."

"I think this is a very wonderful lesson for the young ones about what the older generation has done for us."