Saudi Arabia is the most important country and a largest one in the Arabian Peninsula. It is ninety per cent dry, hot, and inhospitably deserted. Most of the Saudi people are Arab Muslims. Riyadh, Saudi Arabia's capital is a modern city lying among oases of orchards and palm groves. It is the centre for commerce and government. Farming employs one-eighth of its work forces. Massive irrigation projects made it possible for the Saudi farmers to cultivate cereals, vegetables, and fruits. They take their religion very seriously and interpret the Islamic holy book, Quran strictly. Every year, over two million Muslims visit the kaba shrine in the Great Mosque at Mecca. All Muslims should make a pilgrimage, to Mecca at least once in their lifetime. Saudi Arabia has grown wealthy because of its vast oil reserves. It has world's biggest oil and gas reserve that is quarter of the world's total.