Lower Mesopotamia Persian Gulf and severely limits productivity in the region south of Al Amarah. The salinity is reflected in the large lake in central Iraq, southwest of Baghdad, known as Bahr al Milh (Sea of Salt). There are two other major lakes in the country to the north of Bahr al Milh: Buhayrat ath Tharthar and Buhayrat al Habbaniyah. Lower Mesopotamia Lower Mesopotamia is a historical region of Iraq. Also known as the Sawad and al-'Irāq al-'Arabi ("Arabian Irāq") in the Middle Ages. Lower Mesopotamia was home to ancient Sumerian and Babylonian civilisations. An alluvial plain begins north of Baghdad and
Dara (Mesopotamia) the country of the Arabs from the inroads of the Persians and Saracens". Masons and workers from all over Mesopotamia were gathered and worked with great haste. The new city was built on three hills, on the highest of which stood the citadel, and endowed with great storehouses, a public bath and water cisterns. It took the name "Anastasiopolis" () and became the seat of the Roman "dux Mesopotamiae". According to Procopius, the hasty construction of the original walls resulted in poor quality, and the severe weather conditions of the region exacerbated the problem, ruining some sections. Thus Byzantine Emperor