Pro Natura, founded in 1909 in Basel as Swiss League for the Protection of Nature, is the oldest environmental organisation in Switzerland.

Pro Natura takes care of about 700 nature reserves of various sizes throughout Switzerland (250 square kilometres, of which 60 square kilometres are owned by Pro Natura).

In 1909, representatives of the Swiss Society of Natural Sciences founded the Swiss League for the Protection of Nature (German: Schweizerischen Bund für Naturschutz, French: Ligue suisse pour la protection de la nature) to fund and create the Swiss National Park (inaugurated in 1914). In 2000, Pro Natura launched a campaign supporting the creation of a second Swiss National Park.

In 1947, the Swiss League for the Protection of Nature organised an international conference on the protection of nature in Brunnen. It resulted in the creation of the International Union for Conservation of Nature in 1948.

Between 1958 and 1963, the Swiss League for the Protection of Nature, together with the Swiss Heritage Society and the Swiss Alpine Club, established an inventory of landscapes and natural sites of national importance. Based on it, the Swiss Federal Council published the Federal Inventory of Landscapes and Natural Monuments in 1977.

Since 1995, Pro Natura has been a member of the global environmental network Friends of the Earth. In 1997, the Swiss League for the Protection of Nature adopted the name Pro Natura.

The four main objectives of Pro Natura are:

They reach their objectives through: