Saudi Arabia is a country located in the Middle East, occupying most of the Arabian Peninsula. It is known for its vast deserts, including the Rub' al Khali, or Empty Quarter, which is one of the largest sand deserts in the world. The capital city is Riyadh, and the official language is Arabic. The country is rich in oil reserves, making it one of the leading oil producers globally. Mecca and Medina, two of the holiest cities in Islam, are also located in Saudi Arabia, attracting millions of pilgrims each year for the Hajj pilgrimage.