The Vietnam War was broadcast throughout the world, with images of battles, soldiers and jungles flooding the media. But what we didn't see were the tunnels, passages and caves that played a vital role in Vietnam's survival.

From the massive CuChi tunnel system that gave soldiers the upper hand to the super-bunkers and secret caves used as shelters, discover this hidden underworld of Vietnam and get a glimpse of the country as you have never seen it before.