Khám phá: bốt pháp xây dựng tại núi đôi, sóc Sơn, Hà Nội, Việt Nam, trước và sau 1945,

Discover: The French outpost was built at the Twin Mountains, Soc Son district, Hanoi city. It is said that the outpost was built before and after 1945, during the occupation of Vietnam. It is also associated with the love story of a female student named Tran Thi Bac and a young man named Trinh Khang. They fell in love and got married after three months. The French army shot and killed her. Trinh Khang returned and lost his wife. He was so sad that he looked back at the Twin Mountains and lamented, "The Twin Mountains are still here, I have lost you." The tragic love story has become a legend. The poet Vu Cao wrote the legendary Twin Mountains poem that has touched millions of hearts.