Located in the system of Non Nuoc Cao Bang Global Geopark, Phia Oac - Phia Den National Park stretches over the territory of Thanh Cong, Quang Thanh, Phan Thanh, Hung Dao and Tinh Tuc towns (Nguyen district). Binh), has a total area of ​​over 10,500ha, including 8,146.6ha of natural forest, with a peak of nearly 2,000m above sea level, with many beautiful wild landscapes, cool year-round climate. This place also preserves the primitive forest ecosystem on the high mountains "moss forest" with nearly 2,000 rare and precious species of flora and fauna, many of which are listed in the World Red Book.