Unterwalden (Latinized as Sylvania, later also Subsylvania as opposed to Supersylvania) is the old name of a forest-canton of the Old Swiss Confederacy in central Switzerland, south of Lake Lucerne, consisting of two valleys or Talschaften, now organized as two half-cantons, an upper part, Obwalden, and a lower part, Nidwalden. Unterwalden was one of the three participants in the foundation of the Old Swiss Confederacy, named in the Pact of Brunnen of 1315 with Uri and Schwyz.