Presently, the Hải Vân Quan historical site has undergone significant changes compared to primary historical records from the Nguyễn Dynasty, French sources from the early 20th century, and other documents during the period from 1946 to 1975. In 1918, when H. Cosserat conducted research on Hải Vân Quan, it appeared abandoned, but the structures were relatively clear in terms of location, scale, and construction. However, from 1946 to 1975, Hải Vân Quan and Thiên Hạ Đệ Nhất Hùng Quan were extended upward to increase the height of the gates for enhanced control. Some sections of the walls, terraced systems, internal paths, etc., were dismantled, lowered in height, or newly built away from their original positions.
The strategic points such as artillery positions, headquarters, and arsenals were replaced by new military buildings, barracks, underground warehouses, and gun emplacements constructed by the French and later the U.S. military during their occupation. The entrance to Thiên Hạ Đệ Nhất Hùng Quan was sealed with modern bricks, buried under approximately 2 meters of soil and sand. The Thiên Lý road from the south leading to Hải Vân Quan and from Thiên Hạ Đệ Nhất Hùng Quan to Huế was flattened and filled in. Additionally, around Hải Vân Quan, French and American military units built five bunkers at vulnerable positions to protect the area.
After 1975, new structures like the Viba station, high-voltage power lines, and the Victory Memorial were constructed within the historical site, along with existing French and American military installations. These changes completely altered the original layout of the Hải Vân Quan historical site.
In general, Hải Vân Pass is not only a majestic and top-rated scenic spot in Vietnam - "Thiên Hạ Đệ Nhất Hùng Quan" but also a witness to many glorious achievements in the nation's history, particularly during the resistance wars against the French and the Americans (1946 - 1975).
The Hải Vân Quan historical site has been recognized as a National Heritage, and conservation, restoration, enhancement, and utilization of its values are crucial to restore its inherent significance, contribute to preserving the cultural heritage of the nation, and support economic development during the period of renovation and international integration.
Alongside Lăng Cô - Bạch Mã - Cảnh Dương, Hải Vân Quan is a point of attraction for domestic and international tourists, offering a chance to appreciate the magnificent beauty of mountains, forests, and the sea.