al-Hejaz, also Hijaz ( , literally "the barrier") is a region in the west of present-day Saudi Arabia. Defined primarily by its western border on the Red Sea, it extends from Haql on the Gulf of Aqaba to Jizan. Its main city is Jeddah, but it is probably better known for the Islamic holy cities of Mecca and Medina. As the site of Islam's holy places the Hejaz has significance in the Arab and Islamic historical and political landscape. The region is so called as it separates the land of Najd in the east from the land of Tihamah in the west.