الربع الخالي
The Rub' al Khali (; (), the "Empty Quarter") is the sand desert (erg) encompassing most of the southern third of the Arabian Peninsula. The desert covers some (the area of long. 44°30′−56°30′E, and lat. 16°30′−23°00′N) including parts of Saudi Arabia, Oman, the United Arab Emirates, and Yemen. It is part of the larger Arabian Desert.