Ar-Rub' al-Ḫālī

The Rub al-Khali, or Empty Quarter, is the great sand desert of southern Arabia. In its northern reaches, beyond the oases of Najd, dunes and sand ridges stretch across a vast basin. Their forms and heights vary with the winds, while gravel plains and exposed ground interrupt the sand in places. The scarcity of surface water makes this one of the peninsula's most formidable regions to cross.