The Diemtigtal Nature Park lies between the two mountain chains Niesen and Turnen. The southern end of the valley is formed by the peaks Seehorn, Spillgerte, Rauflihorn and Männlifluh. Männifluh is the highest peak of the valley at 2,652 m a.s.l., whereas Burgholz, characterised by its two mill towers, is the lowest point with 640 m a.s.l.
The Diemtigtal fits exactly the definition of a nature park, thanks to its location surrounded by mountains and forming a natural gate into the valley.
Moreover, the 16 km long Diemtigtal is the largest side valley of the Simmental (Simmen valley). The Nature Park covers the whole of the Diemtigtal (Diemtig valley) and includes the municipalities of Diemtigen and partially Zweisimmen. More precisely, it includes the whole municipality of Diemtigen and, due to landscape reasons, also a part of the municipality of Zweisimmen. This is how the regional Nature Park reaches its size of 135.4 km2.