Zemlyanka is Russian for “dugout”. Partisans usually built their shelter deep in the forest and carefully camouflaged them from ground and air observation. In late 1943 the Romanian Mountain Corps undertook a particularly successful partisan operation in the Yaila Mountains. Reinforced with elements of the 2nd Motorized Cavalry Division created a 65 square kilometer perimeter. On 29 December, the 2nd Mountain Division began the assault sweep through the encircled area.