Overview of Vietnam grottoes and caves
Vietnam grotto contains the system of grottoes and caves. They are mainly located in the north part of the country due to the gathering of limestone range. Grotto is the natural empty space or dug in the land or mountains by people. Meanwhile, empty space in the Limestone Mountains is caves. Vietnam’s system of grotto is often the caves which are deeply located in the Limestone Mountains with the structure of karst. Two natural wonders of the world which are Ha Long Bay and Phong Nha – Ke Bang Natural Park are the landscape with famous grottoes. Vietnam is going to nominate Trang An grotto system to be the natural wonder of the world.
Limestone Mountain in Vietnam has quite big area with 50,000 to 60,000 km2. Those occupy nearly 15% of the mainland which mainly located in North (Ha Giang, Cao Bang, Lang Son provinces), East North (Quang Ninh province), West North (Lai Chau, Lao Cai, Son La, Hoa Binh, Ninh Binh provinces) and North of Central part (Quang Binh province).
Research of grottoes and caves in Vietnam until 2000 has discovered only 200 grottoes with the main part (90%) is short and medium length (less than 100m) and only 10% of them is the high length (more than 100m). In 2003, in the West North, there are more than 300 grottoes being discovered with many grottoes of more than 1000m length such as Bat grotto, Snake grotto, Thi Doi, Nam Khum etc. Until 2010, only only Quang Binh have discover 300 grottoes in National Park Phong Nha – Ke Bang, Ninh Binh with over 100 grottoes which locate in Trang An. That increase the number of Vietnam’s grotto to nearly 1000.
Vietnam’s grottoes are often in the foot or in the middle of the mountain. Many grottos have the entrance of 110m wide and 120m height such as Bat Grotto in Lang Son. The deepest grotto is Ca grotto – Be grotto with the depth of 123m. Especially, there are many grottoes in Vietnam have the rivers flow underground. Most of Vietnam’s grotto have beautiful landscape and attractive to tourists. Beside the natural beauty of Mother Nature, the grotto also contains archeology vestiges, the cultural and historical vestiges which are special to develop tourism.
The grottoes in Vietnam has not been exploited and taken to use though the number is big. The typical grottoes which are exploited are: Phong Nha cave (Quang Binh province), Huong Tich cave (Hanoi), Nhi Thanh, Tam Thanh (Lang Son province), Son Moc Huong (Son La province), and grottoes and caves in Halong Bay (Quang Ninh province), etc.
The typical grotto and cave zone
Halong Bay with three most typical grottoes: Surprise Grottoes, Thien Cung Cave, Dau Go grotto, and other tens of beautiful grottoes like Bo Nau, Hanh grotto, Trinh Nu grotto, Trong grotto, Tien Long grotto, Ba Hang, Luon grotto, Tien Ong Cave, Tam Cung cave, Lau Dai cave (Castle cave) and Ba Ham, etc. The report of Halong bay administration board showed that they could not list all the caves and grottoes among the 1,969 islets in Halong Bay.