The Great Underground War (2014)

This fascinating 5-part series unearths the untold story about how the Great War went underground - the tales of tunnellers and miners who dug under the enemy when there was no other choice but to attack from beneath. A 5-part series: The Mines of Ypres, The Secret of the Somm, Vauquois, Hill of Death, Monte Paterno, Col di Lana.