Skopje is in the north of the country, in the centre of the Balkan peninsula, and halfway between Belgrade and Athens. The city was built in the Skopje valley, oriented on a west–east axis, along the course of the Vardar river, which flows into the Aegean Sea in Greece. The valley is approximately  wide and it is limited by several mountain ranges to the north and south. These ranges limit the urban expansion of Skopje, which spreads along the Vardar and the Serava, a small river which comes from the North. In its administrative boundaries, the City of Skopje stretches for more than , but it is only  wide.