1. Thang Hen Lake, Cao Bang
Thang Hen is located in Tra Linh District, about 25km far from Cao Bang town with 3000m in length and 1000m in width. The Thang Hen lake system is made up of 36 small natural lakes on the mountain. All the lakes are connected through caves and underground passageways. In the rainy season, water levels rise to form a single lake, which meanders through a valley of karst peaks for over 300km. Thang Hen Lake is definitely beautiful with its sapphire-green surface. The surrounding green forest is full of local wildlife and many species of insects and the spectacular rock formations, making it a must-visit destination.
2. Am Tien Cave, Ninh Binh
Am Tien cave is located in Hoa Lu ancient capital relic, Ninh Binh province, about 100km from Hanoi. It is the place which Dinh Tien Hoang King (who reigned from 968 to 979) raised tigers, built execution ground and also where the dowager Duong Van Nga Empress (reign 979-980) led a religious life in her old age.
Am Tien Cave is surrounded by mountains and on the foot of the mountain is a green lake with the green clear water, allowing visitors to see its bottom with lots of water plants. Because of its mysterious beauty and ancient landscape, Am Tien Cave is also called Tuyet Tinh Coc and this is also a favorite place for many couples who want to take a wedding photo.
3. Trai Son Mountain, Hai Phong
This blue glow lake is located in Thuy Nguyen district, Hai Phong province. It attracts a lot of people, especially the young coming here to witness the water and take photos. The color of water is caused by the limestone rocks surrounding the quarry. The limestone leaches calcite crystals into the water, turning its color a bright turquoise. Even though the lake creates a beautiful scenery, it might contain a lot of harmful chemicals to human’s health due to mining process.
4. Ta Pa Lake, An Giang
Situated on the top of Ta Pa Mountain, An Giang province, Ta Pa lake is famous for its beauty with clear emerald water due to the influence of mountain mining. Lake-bottom rocks add many colors to the scene including light blue, black, dark orange and light yellow. When the sky is clear, the lake surface reflects the pastoral setting making the lake look like a giant marble face.
There is an old Khmer pagoda, called Chun Num on the mountain with the unique architecture. Standing in Ta Pa, visitors will have a great chance to admire vast fields, rolling mountain ranges and the endless stretch rows of trees.