 The visually dominating figure, which would come to be a familiar landmark for soldiers fighting the war for the DMZ, sits just one kilometer from the vital Route 9.Impressive as it was within the immediate vicinity, the Rockpile is overshadowed by other, much higher hills in nearly every direction.To the Rockpile's northwest is Dong Ke Soc mountain that stands at over 2,200 feet (685 meters), to the direct north is Nui Cay Tri (later known as Mutter's Ridge after the radio call sign of the 3rd Battalion, 4th Marines who would defend it), and to the northeast is Dong Ha Mountain.