Bern is the 'federal city' (de facto capital) of Switzerland. Founded in 1191, the city is built on a narrow hill loop surrounded on three sides by the Aare River. Legend has it that the city was named after a bear (Bär in German), which was the first animal the founder caught in the area; today, bears are still kept in the city's Bear Park. Bern’s Old Town is a UNESCO World Heritage site, preserved with its medieval 15th-century arcades and Renaissance fountains. A famous resident of Bern was Albert Einstein, who developed his Theory of Relativity while working at the patent office here in 1905. Switzerland’s unique political system means that Bern is not a traditional 'power capital'; the country has no single head of state, but rather a seven-member Federal Council. The city serves as a symbol of Swiss neutrality and stability, nestled between the Jura Mountains and the Swiss Alps.