In ancient times usually Iranian were considering there is a long sea all around the world called(Mohit) ocean and from this long round ocean separate two large sea called Persian sea and (Rum ) Mediterranean sea. even in Quran it mentions 2 sea (Bahrain) some other geographer mentioned the world has 7 seas and the most important seas are : Bahr Mohit (ocean) , Persian sea ,Mediterranean sea , Africa sea (Habasha) and china sea.