Rub' al Khali

The largest continuous sand desert in the world, the Rub' al Khali covers approximately 650,000 square kilometres across southern Saudi Arabia and extending into adjacent countries. Dune forms range from the relatively modest star and seif dunes of the margins to massive mega-dunes rising over 250 metres near the Omani border. Human habitation is essentially absent beyond occasional Bedouin movements, and on clear nights the sky above is among the darkest and most star-dense accessible from the Arabian Peninsula.