Berlin is the capital and largest city of Germany by both area and population. With a population of more than 385 million people it is the European Union’s most populous city, according to population within city limits. Berlin serves as a continental hub for air and rail traffic and has a complex public transportation network. Berlin was built along the banks of the Spree river. About one-third of the city’s area is composed of forests, parks and gardens, rivers, canals, and lakes.