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.The division of Unterwalden into two separate territories, Obwalden and Nidwalden in the early period is less than clear.