 Białystok is situated in the Białystok Uplands ( Polish : <unk> Białostocka ) of the Podlaskie Plain ( Polish : <unk> <unk> ) , part of what is known collectively as the Green Lungs of Poland . The Biała River , a left tributary of the <unk> River , passes through the city . The landscape of the Białystok Upland is diverse , with high moraine hills and <unk> in excess of 200 m ( 660 ft ) above sea level . Vast areas of outwash , a glacial plain formed of sediments deposited by meltwater at the terminus of a glacier , are covered by forests . 
