. >> we know that when estivate, we will find things but the war was about men and flesh and blood. >> is it likely that any of those live here? >> this man certainly does. very close to here, 80 feet down, this man still is there. this is a tiny fraction of those men that came through here. >> are around the glory hole, explosions and artillery fire tore up the ground, and yet the german defenses held. this led to the heaviest losses sustained. the villagers have always known that tunnels crisscrossed their farmland. miners and engineers burrowing deep to explosives. now, for the first time, others will retrace those journeys. >> the other thing i have found is another piece of graffiti from 1916, a soldier from the border regiment. >> earlier exploration is recovering traces of the men who disappeared. in tunnels, where miners trembled beneath the thunder of the guns, a desperate palm on the top. >> with on the place you are detained, do not look around or remain. >> the man who wrote this is in the mouth of hell. >> this is only the beginning and for the coming months and years, th