The border between the Syrian Arab Republic and the Republic of Turkey is about long. It runs across Upper Mesopotamia for some 400 km, crossing the Euphrates reaching as far as the Tigris, following the Southern Turkish stretch of the Baghdad Railway roughly along the 37th parallel  between the 37th and 42nd eastern meridians. In the west, it surrounds the Turkish Hatay Province, following the course of the Orontes River and reaching the Mediterranean coast at the foot of Jebel Aqra.