The journey begins at the Lang Mon ancient coral geosite (Minh Tam Commune), where numerous coral and brachiopod fossils dating back approximately 400 million years have been preserved. It may be difficult to imagine that today’s rugged mountains were once a shallow tropical sea, where coral reefs flourished in clear, shallow, sunlit waters. Preserved within limestone layers, these fossils not only provide evidence of an ancient ocean but also help scientists reconstruct palaeoenvironmental conditions and determine the age of geological formations. The present-day Phja Oac mountain landscape is the result of continuous tectonic movement, uplift, and transformation of the Earth’s crust.

Continuing the journey, the Mao Ga Mountain panorama (Tam Kim Commune), the Dragon-Back panorama (Nguyen Binh Commune), and Tinh Tuc Hanging Valley (Tinh Tuc Commune) provide an opportunity to observe the effects of geological and surface processes in shaping the landscape. Visitors can see differences in rock types, fault zones, and the long-term processes of weathering, denudation, and erosion. Distinctive mountain forms, winding ridgelines, steep slopes, and valleys situated at unusual elevations are the result of millions of years of continuous movement and evolution of the Earth’s crust. Each landscape is not only visually striking but also provides tangible evidence of the region’s long geological history, helping explain how the present-day mountain landscape of western Cao Bang was formed.

Another prominent geological feature of the Western Route is the formation of the Phja Oac granite massif. Approximately 85–95 million years ago, magmatic activity deep within the Earth generated intense changes in the surrounding rocks, giving rise to massive granite bodies and contributing to the formation of various economically valuable mineral deposits, including tin, tungsten, and gold. The abundance of mineral resources provided the foundation for the development of mining in the Phja Oac–Tinh Tuc area throughout the twentieth century, leaving behind a remarkable legacy of geological, historical, and industrial heritage.

Today, the Tinh Tuc Tin Mine Geosite (Tinh Tuc Commune), the Ban O Tungsten Mine, and the Lung Muoi Tungsten Mine (Thanh Cong Commune) still preserve numerous traces of past mining activities. Mine workings, ore-processing areas, and surviving technical structures reflect a vibrant period in the development of the local mining industry. They also help visitors understand the relationship between magmatic processes and mineral formation, as well as the role of natural resources in the socio-economic development of the region.

Beyond its geological significance, the Phja Oac mountain area is also characterized by distinctive ecosystems shaped by changes in elevation. From the foothills to the summit of Phja Oac at 1,935 metres above sea level, temperatures gradually decrease while humidity increases, creating distinct vegetation belts ranging from tropical evergreen forests to subtropical forests, mossy forests, and high-elevation dwarf forests. The diversity of terrain, climate, and soils supports rich ecosystems containing a variety of rare and valuable plant and animal species, while forming the core zone of Phja Oac–Phja Den National Park.

Amid the forests of Phja Oac, the Red House Villa is one of the remaining structures that bears witness to the period when the French exploited mineral resources and developed a mountain resort in the early twentieth century. Built in a European architectural style, the villa is nestled among pine forests and the cool climate characteristic of the high mountains. After more than a century, the building still stands quietly within the mountain landscape as a witness to history, reflecting the transformations of the Phja Oac area through different periods.

The Kolia Tea Plantation Geosite is a representative stop in the Phja Den mountain area, where natural landscapes, distinctive agricultural production, and ecotourism have been developed in harmony. Amid lush tea hills at elevations above 1,300 metres, visitors can walk among the tea plantations, taste Phja Den tea, admire the sea of clouds, and experience the tranquil beauty of the high mountains. The development of tea cultivation in association with landscape conservation and sustainable tourism has enhanced the value of local products, created livelihoods for local communities, and enriched the visitor experience along the Western Route of Non Nuoc Cao Bang UNESCO Global Geopark.

The Western Route also takes visitors back to important milestones in Vietnam’s national history. Tran Hung Dao Special National Relic Site (Tam Kim Commune) is where the establishment and early activities of the Vietnam Propaganda Liberation Army, the predecessor of the Vietnam People’s Army, are commemorated. The site is also closely associated with the revolutionary life and career of General Vo Nguyen Giap, an outstanding student of President Ho Chi Minh. Amid the primeval forest, each place name preserves memories of the difficult yet heroic early days of the Vietnamese revolutionary movement.

The journey continues to Phai Khat Post (Tam Kim Commune), where the first battle of the Vietnam Propaganda Liberation Army took place on 25 December 1944. Although relatively small in scale, the victory at Phai Khat demonstrated the growing strength and capabilities of the revolutionary armed forces and marked the beginning of a series of victories in the struggle for national independence. Today, Tran Hung Dao Special National monument and Phai Khat post serve as important sites for historical education, helping to foster patriotism and revolutionary traditions among younger generations.

Alongside its geological, landscape, and historical values, the Western Route also offers visitors an opportunity to discover the distinctive cultural identity of the Dao Tien community. Traditional brocade embroidery and beeswax batik have been passed down through generations, with each traditional costume representing the culmination of entirely handmade processes of weaving, indigo dyeing, and embroidery. Today, alongside the development of community-based tourism, these traditional crafts are being preserved and promoted through hands-on experiences, contributing to local livelihoods while giving visitors an opportunity to learn about the distinctive cultural heritage of the Dao Tien community within Non Nuoc Cao Bang UNESCO Global Geopark.

The Western Route offers far more than an exploration of geological heritage, landscapes, and biodiversity. It is also a journey into revolutionary history and the cultural identities of local ethnic communities. The harmonious connection among nature, history, and people gives the route its distinctive appeal, contributing to the recognition of the outstanding values of Non Nuoc Cao Bang UNESCO Global Geopark while promoting sustainable tourism development that links heritage conservation with local socio-economic development.