Obwalden or Obwald ( ; ; ; ) is one of the 26 cantons forming the Swiss Confederation. It is composed of seven municipalities and the seat of the government and parliament is in Sarnen. It is traditionally considered a "half-canton", the other half being Nidwalden. Obwalden lies in Central Switzerland and contains the geographical centre of Switzerland. It is bordered by the canton of Lucerne to the north, the canton of Nidwalden and Uri to the east and the canton of Bern to the south. The canton is essentially in the valley of the Sarner Aa south of Lake Lucerne, with an exclave around Engelberg. It is one of the smallest cantons. The largest town is Sarnen, followed by Kerns and Alpnach. Together with Nidwalden, Obwalden was part of the forest canton of Unterwalden, 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, Nidwalden and Obwalden, appears to develop over the course of the 14th and 15th centuries. History Obwalden is one of the two valleys, along with Nidwalden, that make up Unterwalden. Throughout its history, the political situation and the extent of its independence have varied widely. Between 1291 and 1309, Unterwalden joined the nascent Swiss Confederation. During that time Obwalden was known as Unterwalden ob dem Kernwald and Nidwalden was Unterwalden nit dem Kernwald. Unterwalden's votes in the Tagsatzung were split between the two valleys. Between 1798 and 1803 it became the District of Sarnen in the Canton of Waldstätten. From 1803 until 1999 it was the half-canton of Obwalden. In 1999, the new Federal Constitution eliminated the half-canton designation and made Obwalden a full canton, though they still shared representation in the Council of States and only had half a vote. Due to the complex history of Obwalden there will be some overlap between the histories of Obwalden, Nidwalden, and Unterwalden. Prehistory The earliest archaeological traces in Obwalden is a stone knife from the 8th millennium BC, which was found in Brand by Lungern. Two Horgen culture sites from the 4th millennium BC have been found in the Canton. An ax and two bone blades were found in Giswil and a hammer-ax was found in Wilen. It appears that the valleys in Obwalden were at least temporarily inhabited during this time, but