Tigris–Euphrates river system through the central plain and combine at Al-Qurnah to form the Shatt al-Arab and discharge into the Persian Gulf. The region has historical importance as part of the Fertile Crescent region, in which civilization is believed to have first emerged. The ecoregion is characterized by two large rivers, the Tigris and Euphrates. The rivers have several small tributaries which feed into the system from shallow freshwater lakes, swamps, and marshes, all surrounded by desert. The hydrology of these vast marshes is extremely important to the ecology of the entire upper Persian Gulf. Historically, the area is known as Mesopotamia. As
Euphrates Tunnel chariots and connected a major temple with the royal palace on the other shore of the river, it was supposedly lined with brick and waterproofed with asphalt. A description of the tunnel as being built and used by Queen Semiramis is given by Diodorus (fl. 50 BCE) in the "Bibliotheca Historica": Philostratus (d. 250 CE) also describes the tunnel's construction in the "Life of Apollonius of Tyana": Euphrates Tunnel The Euphrates Tunnel was allegedly a tunnel which was built under the Euphrates river to connect the two halves of the city of Babylon, in the old Mesopotamia. Archaeologists believe it