Hoa Lu Cave, also known as Thung Lau (Lau Valley) or Thung Ong (Ong Valley), is located in Gia Hung Commune, Gia Vien District, Ninh Binh Province.

Hoa Lu Cave, also known as Thung Lau (Lau Valley) or Thung Ong (Ong Valley), is located in Gia Hung Commune, Gia Vien District, Ninh Binh Province.

Hoa Lu Cave was the first base of the Dinh Bo Linh’s troops with the mission of reuniting the country in the 10th century. The Cave is about 15 kilometers from Hoa Lu Ancient Capital and 20 kilometers from Ninh Binh City by road to the north.

Although called a cave, this relic is actually a valley of about 16 acres, surrounded by arc-shaped mountains. The four side of cave are surrounded solidly by mountains, there is only one small entrance about 30 meters high. Thung Lau and Thung La area used to be the place where King Dinh hid special elite troops to use when necessary.

Hoa Lu Cave was the original base of Dinh Bo Linh, but also related to Nguyen Minh Khong. According to legend, Thung Lau Temple in the middle of Hoa Lu cave was originally a place for worshipping Dinh Bo Linh. After that, people worshiped King Dinh at the mutual temple of 3 communes and took Nguyen Minh Khong's incense sticks at Xa Temple to worship here.

Hoa Lu Cave festival is held in this relic every spring. The festival is relatively similar to the Hoa Lu Ancient Capital Festival but in smaller scale. With these values, Hoa Lu Cave was recognised as National Historical Relic by the Ministry of Culture and Information in 1996.