To the north and east, wide forested hills (''Marka'') rise above the city giving the location the shape of a giant amphitheatre. The urban municipality (''bykommune'') of Oslo and county ''fylke'' of Oslo are two parts of the same entity, making Oslo the only city in Norway where two administrative levels are integrated. Of Oslo's total area,  is built-up and  is agricultural. The open areas within the built-up zone amount to .