Cities (2003 est.): Capital--Riyadh. Other cities--Jeddah, Makkah, Dammam/Khobar/Dhahran.
Terrain: Primarily desert with rugged mountains in the southwest.
Climate: Arid, with great extremes of temperature in the interior; humidity and temperature are both high along the coast.
Saudi Arabia is known as the birthplace of Islam, which in the century following Muhammad's death in 632 A.D. spread west to Spain and east to India. Islam obliges all Muslims to make the Hajj, or pilgrimage to Makkah, at least once during their lifetime if they are able to do so. The cultural environment in Saudi Arabia is highly conservative; the country adheres to a strict interpretation of Islamic religious law (Shari'a). Cultural presentations must conform to narrowly defined standards of ethics. Men and women are not permitted to attend public events together and are segregated in the work place. Most Saudis are ethnically Arab. Some are of mixed ethnic origin and are descended from Turks, Iranians, Indonesians, Indians, Africans, and others, most of whom immigrated as pilgrims and reside in the Hijaz region along the Red Sea coast. Many Arabs from nearby countries are employed in the kingdom. There also are significant numbers of Asian expatriates mostly from India, Pakistan, Bangladesh, Indonesia, and the Philippines. There are less than 100,000 Westerners in Saudi Arabia. Saudi Arabia's 2004 population was estimated to be about 26.7 million, including about 7 million resident foreigners. Until the 1960s, most of the population was nomadic or seminomadic; due to rapid economic and urban growth, more than 95% of the population now is settled. Some cities and oases have densities of more than 1,000 people per square kilometer (2,600 per sq. mi).