Phja Oắc – Phja Đén National Park, established in 2018, is located in the communes of Thành Công, Phan Thanh, Tam Kim, and Tĩnh Túc, approximately 73 km west of Cao Bằng province center via Provincial Road 212 and National Highway 34. Visitors can travel from Tuyên Quang via National Highway 34 through Bảo Lâm and Bảo Lạc; or from Ba Bể Lake (Thái Nguyên province) via National Highway 3, then crossing the Kolia Pass to reach Phja Oắc – Phja Đén National Park.

Visiting Phja Oắc – Phja Đén at any time of year is incredibly enjoyable. Especially in winter, when temperatures drop below 0°C, visitors can witness frost covering vast areas of hills and mountains. The park also preserves many forest ecosystems, particularly dwarf forest ecosystems, with nearly 2,000 rare and endangered plant and animal species, many of which are listed in the World Red Book. Many famous landmarks such as Phja Oắc peak, approximately 1,931 m high – where the Vietnam Voice Radio and Television transmission tower is located, Kolia Pass, the old French villa, Vọng Tiên Cung ancient temple, Kolia tea plantation… have created a magnificent landscape complex.