What is Saudi land covered by?

Saudi Arabia is covered by desert, with the exception of the far south-western region, which is mountainous. The country's largest desert is the Rub' al Khali, which covers much of the southern part of the country and extends into Oman and Yemen. The Rub' al Khali is one of the largest sand deserts in the world, covering an area of about 650,000 square kilometers (250,000 square miles). Other deserts in Saudi Arabia include the Ad Dahna, which lies to the east of the Rub' al Khali, and the Nafud, which lies to the north. The mountainous region in the far south-west of the country is known as the Hijaz Mountains. The highest point in Saudi Arabia is Jabal Sawda, which is located in the Hijaz Mountains and has a peak elevation of 3,133 meters (10,279 feet).