Saudi Arabia, officially known as the Kingdom of Saudi Arabia, is geographically the largest sovereign state in Western Asia, second-largest in the Arab world, and the twelfth largest in the world, with a population of over 34 million people. An Islamic country with an absolute monarchy system, Saudi Arabia is known as The Land of the Two Holy Mosques, in reference to Al-Masjid al-Haram and Al-Masjid an-Nabawi, the two holiest places in Islam. Saudi Arabia is the largest country in the world without a river, having the largest sand desert in the world. The country was rated as the best place to do business in the Middle East, while also providing free public health care services. Saudi Arabia possesses approximately 22% of the world's oil reserves. It is the world's largest exporter of petroleum liquids and relies on the oil industry for almost half of its GDP.