The historical site and beautiful landscape of Yen Tu covers an area of about 9,200 hectars on which religious architectural constructions are built such as pagodas, temples and towers from the Ly dynasty, from Bi Thuong (Doc Do) to the mountain top of Yen Tu (Phuong Dong ward, Thuong Yen Cong commune (Uong Bi city) and Hong Thai Dong commune (Dong Trieu district), Quang Ninh province.)
According to historical books, about 1,000 years ago Yen Tu was considered “the fourth blessing land of Giao Chau” and “in the third year of Tu Duc’s reign, Yen Tu Mountain was listed in the book of well known beautiful places”.
The historical site of the Tran dynasty in Dong Trieu is located in old An Sinh, now known as Dong Trieu, and covers an area of about 11,000 hecta of which the majority belongs to the An Sinh, Trang An, Tan Viet, Thuy An and Binh Khe communes, the Dong Trieu district and Quang Ninh province. The site is a complex of graves of Kings, temples, shrines, pagodas and towers.
According to VietKings (Kyluc.vn)