As the name suggests, the Sonnenberg is exposed to constant, highly intense sunshine. It is hot, barren and dry in the area along this mountain which stretches over 50 kilometres between Partschins and Mals,

These slopes have always been favourite grazing grounds for goats and sheep. This meant that a broad strip of vegetation was eaten clean over time. The meagre soil was eroded and washed out. The intense sunshine played a part too.

The soil temperature can reach 70 degrees in summer, while during winter severe frosts are common. The plant life has been forced to adapt to these climatic conditions. This means that walkers on the Sonnenberg will find a unique, steppe-like landscape with dry grasses, blooming herbs and shrubs. Biologists are also highly interested in the area's special flora.