Greater Burgan is one of the world's largest oil fields. It ranks second behind Ghawar in neighbouring Saudi Arabia, but is widely regarded as the largest onshore sandstone oil reservoir in the world. The field extends around 800 km2. It is comprised of three separate depth-structural closures - Ahmadi, Burgan and Magwa - near the crest of the north-south trending Kuwait Arch. It lies south of Kuwait city, adjacent to the country's southeast coast, at the head of the Gulf. The field dominates Kuwait's upstream industry, currently making up over 50% of the country's production.