Berlin is the capital and the largest city of Germany, as well as one of its 16 constituent states. With a steadily growing population of approximately 3.7 million, Berlin is the second most populous city proper in the European Union behind London and the seventh most populous urban area in the European Union. Located in northeastern Germany on the banks of the rivers Spree and Havel, it is the centre of the Berlin-Brandenburg Metropolitan Region, which has roughly 6 million residents. Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. Around one-third of the city's area is composed of forests, parks, gardens, rivers, canals and lakes.