Vast desert, south-central Arabian Peninsula .
It covers about 250,000 sq mi (650,000 sq km), mainly in southeastern Saudi Arabia, and has lesser portions in Yemen, Oman, and the United Arab Emirates. It is the largest area of continuous sand in the world and occupies more than one-fourth of Saudi Arabia. It is virtually uninhabited and largely unexplored. In 1948 Al-Ghawār , the world's largest oil field, was discovered there.