Saudi Arabia is a veritable "oil kingdom". Saudi Arabia is the largest producer of desalinated seawater in the world, and its desalinated seawater accounts for about 2 1% of the world total. Saudi Arabia pursues a free economic policy. Mecca is the birthplace of Muhammad, the founder of Islam, and a holy place for Muslims to make pilgrimages. Economic development focuses on industry, and petroleum and petrochemical industry is the lifeblood and main economic source of the national economy.