Jīlū /dʒəluː/ was a district located in the Hakkari region of upper Mesopotamia in modern-day Turkey. Before 1915 Jīlū was home to Assyrians and as well as a minority of Kurds. There were 20 Assyrian villages in this district. The area was traditionally divided into Greater and Lesser Jīlū, and Ishtāzin - each with its own Malik, and consisting of a number of Assyrian villages. In the summer of 1915, during the Assyrian Genocide, Jīlū was surrounded and attacked by Turkish troops and neighboring Kurdish tribes under the leadership of Agha Sūtū of Oramar.
After a brief struggle to maintain their positions, the Assyrian citizens of Jīlū were forced to flee to Salmas in Iran along with other refugees from the Hakkari highlands. Today their descendants live all over the world including Iraq, Syria, Iran, Lebanon, Russia, the United States, Canada, Australia and Europe. In Syria's al-Hasakah Governorate there are two villages, Tel-Gorān and Abū-Tīnā, established in 1935 by Jīlū refugees from Iraq on the banks of the Khabur River.
The Jīlū district is home to the second highest mountain range in Turkey, the Cilo-Sat range, which are an eastern extension of the Taurus Mountains. The highest peak in the Cilo-Sat range is Ţūrā Shinnā d-Jīlū (also known as Cilo dağı, maximum elevation 4,168 m), from the summit of which one can see as far as the city of Mosul in Iraq. The massif is composed of metamorphic schist, dolomitic limestone, and porphyrites, and is deeply scored by the gorges of tributaries to the Great Zab River. Above 3,500 m there are a number of ancient glaciers and the nature is alpine. The southern slopes of the massif are covered with broad-leaved forests (primarily oak), and the northern slopes are covered with steppes and shrub thickets where the inhabitants of Jīlū and Dīz would graze their herds during the summer.