Bern lies on the Swiss plateau in the Canton of Bern, slightly west of the centre of Switzerland and 20 km (12 mi) north of the Bernese Alps. The countryside around Bern was formed by glaciers during the most recent Ice Age. The two mountains closest to Bern are Gurten with a height of 864 m (2,835 ft) and Bantiger with a height of 947 m (3,107 ft). The site of the old observatory in Bern is the point of origin of the CH1903 coordinate system at 46°57′08.66″N 7°26′22.50″E.
The city was originally built on a hilly peninsula surrounded by the River Aare, but outgrew natural boundaries by the 19th century. A number of bridges have been built to allow the city to expand beyond the Aare.
Bern is built on very uneven ground. There is an elevation difference of several metres between the inner city districts on the Aare (Matte, Marzili) and the higher ones (Kirchenfeld, Länggasse).
Bern has an area, as of 2009, of 51.62 square kilometers (19.93 sq mi). Of this area, 9.79 square kilometers (3.78 sq mi) or 19.0% is used for agricultural purposes, while 17.33 square kilometers (6.69 sq mi) or 33.6% is forested. Of the rest of the land, 23.25 square kilometers (8.98 sq mi) or 45.0% is settled (buildings or roads), 1.06 square kilometers (0.41 sq mi) or 2.1% is either rivers or lakes and 0.16 square kilometers (0.062 sq mi) or 0.3% is unproductive land.[11]
Of the developed, 3.6% consists of industrial buildings, 21.7% housing and other buildings, and 12.6% is devoted to transport infrastructure. Power and water infrastructure as well as other special developed areas made up 1.1% of the city, while another 6.0% consists of parks, green belts and sports fields. 32.8% of the total land area is heavily forested. Of the agricultural land, 14.3% is used for growing crops and 4.0% is designated to be used as pastures. The rivers and streams provide all the water in the municipality