Formally, Switzerland does not have a capital city, its de facto function is performed by Bern.

An excerpt from the article 45 facts about Switzerland

Bern is the fourth largest and most populous city in Switzerland, the seat of government, and the capital of the canton of Bern. The city was founded in 1191 by Berthold V, Duke of Zähringen, and according to legend, he named it Bern (bear) because he killed a bear there while hunting. Today, the bear is included in the city's coat of arms and is the city's mascot. The city lies on the Aare River, which divides it into two parts connected by bridges. Bears have been kept in the enclosure by the river since the 19th century. Bern is an important transport hub and is the seat of central authorities, foreign companies, and international organizations. It became the seat of government in 1848. The main attraction of Bern is the medieval old town inscribed on the UNESCO World Cultural Heritage List, as well as Albert Einstein's house, where the physicist created the theory of relativity in 1905.