The gorge carved by the River Aar through the Kirchet constriction between Meitringen and Innertkirchen is one of the great geological curiosities of the Bernese Oberland. It is possible to access the narrowest section of the gorge, where its almost vertical sides hewn by erosion are very impressive. More striking still is the diffused light bathing the bottom of the gorge where the jade-green waters of the Aar flow.