The Wildnispark spans the Sihlwald forest (Alte Sihltalstrasse 13, 8135 Sihlwald, Tel: 044 722 55 10) and the smaller Langenberg park. The latter dates back to 1869, when the city council agreed that the area could be turned into a wild garden.

Starting with red deer, the animal population now includes, elk, bears, wolves, wild boar and lynxes. The Silhwald is the one of the largest deciduous forests in this part of Switzerland, running through it is are forest trails and there is a visitor centre (open March-Oct Tues-Sat 12pm-5.30pm; Sun & public holidays 9am-5,30pm) with information on the park, museum and café.