In the Avesta, reference is made to seven karshvar (Avestan: 𐬐𐬀𐬭𐬀𐬱𐬀𐬎𐬎𐬀𐬭𐬀, romanized: karšvar, lit. 'delineated land' > Persian: kišvar), climes or zones, organizing the world map into a seven-storied ziggurat representing the cosmic mountain. The world is referred to as the haft keshvar "seven climes". The word has also been translated as "region", "state" or "continent".
The Avesta describes the karshvar as superimposed concentric circles one above the other, with increasing size. These are separated by waters, mountains or forests.