The Relic situates at an altitude of 61.0 m compared to the sea level, obstructing the artery traffic routes from Hai Duong to Quang Ninh both on road way and waterway. Shortly after invasion of Vietnam and started coal mining, the French colony started construction of solid trenches, fortifications and blockhouses to serve the invasion war and pillaging of the natural minerals and resources in Dong Trieu. On May 07th 1954, the Dien Bien Phu campaign was totally triumphed, the Don Cao was under control of the revolutionary administration. Today, Don Cao is belonging to the administration area of Hong Phong Commune and Dong Trieu Ward.