Kallio is a district and a neighbourhood in Helsinki, the capital of Finland, located on the eastern side of the Helsinki peninsula about one kilometre north from the city centre. It is one of the most densely populated areas in Finland. Kallio is separated from the city centre by the Siltasaarensalmi strait, over which is a bridge called Pitkäsilta. Traditionally, the bridge symbolizes the divide between the affluent centre and the more working class areas around Kallio.