The kingdom's main oil and gas fields are located in the Eastern Province with sites such as the Ghawar Field, the largest onshore oil field in the world and the Safaniya oil field, the largest offshore oil field in the world. Petroleum is refined in various refineries spread across the kingdom and shipped to dozens of countries from port cities such as Ra's Tanura. The East–West pipeline enables efficient transport of oil from the eastern oil fields and refineries to the western refineries and ports, such as Rabigh and Jeddah.