It is located in Ninh Binh province, near the village of Tam Cốc. The closest city is Ninh Binh. It consists of two distinct attractions: Tam Cốc, a flooded cave karst system; and Bích Động, a series of mountain pagodas.
Tam Cốc, literally "three caves", consists of three natural caves — Hang Cả, Hang Hai, and Hang Ba — on the Ngô Đồng River. Tourists are taken in small boats along the river from the village of Van Lam, through rice fields and limestone karsts, through the caves, and back. Local women serve as guides and attempt to sell embroidered goods to their passengers.
The area is nicknamed "the inland Ha Long Bay".
According to VietKings (Kyluc.vn)