From AllTrails:

20.4-km loop trail near Willerzell, Schwyz. Generally considered a moderately challenging route, it takes an average of 6 h 2 min to complete. This is a popular trail for birding, hiking, and running, but you can still enjoy some solitude during quieter times of day. The best times to visit this trail are April through November.

A great circular hike directly on the Sihlsee in the canton of Schwyz. The path leads along some paved roads, but mostly along forest and mountain paths. The route starts in Willerzell and leads directly along the Sihlsee for 2 km. Then it goes to the Stöcklichrüz (1247 m) and on to the Sattelegg (1190 m). Visitors can expect a wonderful view of Lake Sihl and Lake Zurich.