The world’s largest sand mass is Rub’ al Khali or “the Empty Quarter”. It stretches over the Arabian Peninsula covering most of Saudi Arabia. The sand sea is almost empty of humans, as well as of visible flora and fauna due to extreme heat. It’s known for abundant sand, geological formations and many oases. The dunes are of five different sorts used as a way of dividing the desert accordingly to areas with high and large dunes, steep pyramid dunes, wavelike dunes, domal dunes or diagonal dunes.