Birtha (Mesopotamia) bastions are quite traceable. There are the ruins of a vaulted secret staircase, leading down from the heart of the citadel to the water's edge. Birtha (Mesopotamia) Birtha () was an ancient fortress on the river Tigris, which was said to have been built by Alexander the Great. It would seem, from the description of Ammianus, to have resembled a modern fortification, flanked by bastions, and with its approaches defended by out-works. Shapur II here closed his campaign in 360, and was compelled to retire with considerable loss. D'Anville and Edward Gibbon both identify Birtha as modern-day Tikrit, Iraq. The
History of Mesopotamia southeastern Turkey date to the PPNA/Early PPNB and represent, according to the excavator, the communal efforts of a large community of hunter-gatherers. The Fertile Crescent was inhabited by several distinct, flourishing cultures between the end of the last ice age (c. 10,000 BC) and the beginning of history. One of the oldest known Neolithic sites in Mesopotamia is Jarmo, settled around 7000 BC and broadly contemporary with Jericho (in the Levant) and Çatal Hüyük (in Anatolia). It as well as other early Neolithic sites, such as Samarra and Tell Halaf were in northern Mesopotamia; later settlements in southern Mesopotamia required