Phia Oac Phia Den National Park

On the high ridges of Phia Oắc, the trees stay short. They grow low and close together, and moss covers every trunk and branch. This is how a forest survives where the cold is hard, the fog is thick and the wind is strong on the mountaintop. It is called a moss forest, or a dwarf forest, and it is one of the main reasons Phia Oắc - Phia Đén National Park was created.

The Prime Minister signed the decision to found the park in January 2018. It lies in the Nguyên Bình area of Cao Bằng province and covers more than 10,593 hectares, spread across five administrative units. Two of them are the communes of Thành Công and Quang Thành. Two more are the communes of Phan Thanh and Hưng Đạo. The fifth is the town of Tĩnh Túc. Its goals are to protect 90 rare plant species and 58 rare animal species, to guard the forest ecosystem and to develop sustainable ecotourism.

Scientists have recorded 1,289 species of flowering plants here. Of these species, 841 have practical uses. It is a striking number for a mountain area of just over 10,000 hectares.

The park lies within the Non Nước Cao Bằng UNESCO Global Geopark. A UNESCO Global Geopark is an area with landscapes of international geological importance, managed for protection, education and sustainable development. UNESCO recognized this geopark in 2018, and it stands out for its limestone, tropical karst, caves and underground rivers. The park is the high mountain part in the west of that heritage region, where geology and living things form one unusual system.

The most important rock here is the Phia Oắc granite. Granite forms when magma cools slowly deep inside the earth. About 100 million years ago, magma pushed up through the Phia Oắc region and made granite. Over time it also formed mineral deposits such as tin and tungsten. A block of granite shows three basic minerals. The slightly clear white grains are quartz. The small, shiny black flakes are mica. The patches that may be pale pink or faintly red are feldspar.

From that geology comes the history of mining. The French knew of the tin and tungsten here very early. The Bản Ổ Tungsten Mine began operating in 1908. The Lũng Mười Tungsten Mine followed in the 1910s. Today these two old mines are places where visitors can learn how geology, minerals and the region's economic history connect.

The Kolia tea estate stands in Thành Công commune, at a height of more than 1,300 meters. Tea is rarely grown this high, and the climate stays cool all year.

It may seem odd to grow tea in mountains this cold. The reason is the cold itself. Tea grown high and cool grows more slowly, but it gathers more substance, so the taste is stronger and the aroma fuller. This is the economics of altitude.

A one-day route through the Phia Oắc area links 13 places. The morning is for geology and history around Nguyên Bình, such as the fossils of ancient coral at Lang Môn. The afternoon goes into Thành Công, with the Phia Oắc landscape, granite, old mines and a tea estate.

The route is not only for looking at views. It tells one continuous story. Limestone formed in an ancient sea. Then magma pushed up and made granite and ores. The French came to mine them, and local people farmed and protected the land. Today visitors pass through and come to understand a little more about how geology, history and daily life are joined.

Here they cannot be pulled apart. The granite beneath your feet, 100 million years old, gave rise to the mines. The mines drew the French. The French left, and the moss forest grew back over everything, as quiet as if nothing had ever happened. On the summit of Phia Oắc, the dwarf trees wrapped in moss stand in the wind and tell their story in their own shape.