The Sihlsprung is located in the lower part of the Sihltobel, which stretches from Schindellegi to Sihlbrugg. The surrounding towns are Hirzel and Spitze in the north (belonging to the Zurich municipality of Horgen), in the east Schönenberg (belonging to the Zurich municipality of Wädenswil) and in the southwest Menzingen (belonging to the Zug municipality of the same name). The upper gorge entrance is located below the Sihlmatt clearing on the Zug side (around 590 m), where the hiking trail leads through a tunnel. The lower section can be walked on both sides thanks to a bridge, with the path on the left bank running in places through another tunnel that is around 170 meters long. The exit is around 570 m in front of the Ernihalden.
The area around the Sihltobel forms an important, glacially shaped drumlin and moraine landscape that dates back to the Sihl glacier. The Sihlsprung itself, on the other hand, is a fluvial cut in this landscape that emerged after the last glacial period. The gradient of the Sihl is slight, while the Mülibach, which comes from peaks on the side, has a slightly steeper gradient. Two nameless side streams on the Zug side even form small waterfalls. The partly forested, partly rocky steep walls of the gorge (up to 75 meters high) consist of Nagelfluh and are part of the elongated Molasse zone between Höhronen and Baden. A characteristic of the Sihlsprung are the Nagelfluh boulders, some of which are several cubic meters in size, in and next to the river bed.