Nga ba Dong Loc or Monument Nga Ba Dong Loc is a significant historical site located in Ha Tinh province, Vietnam. The monument is situated in the central region of Vietnam, in Huong Loc Commune, Huong Khe District, Ha Tinh province. It is located approximately 25 kilometers (15.5 miles) north of the city of Ha Tinh.
Hoành Sơn Quan is a historic gate located on the summit of Đèo Ngang (Ngang Pass), marking the natural border between Hà Tĩnh and Quảng Bình provinces in central Vietnam. Built in 1833 under the reign of Emperor Minh Mạng of the Nguyễn Dynasty, the gate was constructed to control movement between the northern and southern regions of the country. The gate is about 4 meters high, with walls extending 30 meters on either side, and the words "Hoành Sơn Quan" inscribed above the archway