Vịnh Mốc tunnels

Vịnh Mốc is a village that was suspected by the US to provide supplies to a garrison of a nearby strategically important island. Hence, the village was repeatedly bombed. As reaction the villagers "simply" moved their entire village underground. In three phases they dug tunnels in the soft limestone, providing shelter, communal space, a hospital and even a maternity ward. They survived from 1967 to 1973 with 0 casualties, but "7 tons of bombs on average per person".

Cemetery of "national heros" a bit outside of the village.