Aar valley is a major Switzer alpine valley from Grimsel pass to Thoune.
This this the main access valley to Bernese Alps. All along the valley you can find kilometers (miles) of hiking trail.
The upper part runs through granite mountains and has been used for hydroelectrical equipment. The median part is mostly covered by Thoune and Brienz lake and it's continuation , Meiringen plain. The part arround Meiringen has been called Haslital.