Iraq consists of 18 recognized governorates, also known as "provinces" and 1 partially recognized governorate (Halabja). Per the Iraqi constitution, governorates can form a federal region. Four governorates, Erbil, Sulaymaniyah, Halabja and Duhok, constitute the semi-autonomous Kurdistan Region. Baghdad and Basra are the oldest governorates. The second most-populous one, Ninawa is in the upland region and has a cooler climate of the north-west.