The Chã Grande Trail crosses the slopes and higher areas of Serra d'Arga, through a landscape where the small plateaus known as chãs contrast with steeper slopes and extensive granite outcrops. Along the route, agricultural fields, terraces, woodland, riparian vegetation and mountain areas reveal the natural diversity of the landscape and its long history of human occupation.
The higher areas include Chã Grande and Chã de São João, open plateaus where mountain grasslands and plant communities adapted to wetter soils can be found. At Chã de São João, the landscape opens onto a vast granite surface frequented by herds of garrano horses and where the headwaters of the Âncora River emerge. Mountain vegetation includes species such as arnica and the endemic Carex durieui.
Geology is another distinctive feature of the route. The granite displays forms created by fracturing and erosion, including granite hollows, boulder fields, pseudo-stratification and rock surfaces with varied shapes. The diversity of the underlying geology, which also includes veins and schistose and quartzitic layers, contributes to the geomorphological richness of Serra d'Arga.
The landscape also preserves many signs of the relationship between local communities and the mountains. Churches, chapels, fields enclosed by stone walls, mills, old farmhouses and shepherds' shelters bear witness to ways of life connected with agriculture, pastoralism and the use of natural resources. Among these features are Casa da Eirinha, in Arga de Baixo, and the shepherds' shelter at Alto da Fonte da Urze, one of the few surviving examples in the mountains.
Type: Short Trail (PR) Loop
Distance: 12
Difficulty: Moderate (level 3)
GPS Coordinates: 41°50'42.3"N 8°42'50.5"W