Most people only know the valley of the Sihl from the traffic jams there that are reported on the radio nearly every day. Squeezed in between the Albis mountain range and Lake Zurich, it forms a natural bottleneck on the route from Zurich into Central Switzerland. However, despite all the traffic, there is still unspoilt natural beauty to be found in the lower Sihl valley. On the far side of the Sihl, a lovely trail meanders along beside the river. Beautiful forests line the river-bank. The Sihlwald forest is the largest single area of mixed woodland in Central Switzerland. Nowadays, the forest is protected, but is open to the public thanks to an extensive network of paths. The cycling route from Adliswil along the Sihl up to Sihlbrugg and down on the other side of the valley through the forest to Langnau shows the Sihlwald forest at its best.