Giant dunes some as high as 250 meters are the hallmark of Rub’ al-Khali or the Empty Quarter which covers some 650,000 square kilometres

This vast desert region is in the southern Arabian peninsula and constitutes the largest portion of the Arabian Desert

Almost seventy percent of the Rub’ al-Khali lies in Saudi Arabia, the rest being in Yemen, Oman and United Arab Emirates

While much of the land in Rub’ al-Khali lies below the sea level, in certain part of the west the elevation is as high as 2,000 (610 meters) feet above the sea level, while in the east the elevation drops to about 600 feet (180 meters)

The area, parts of which were once under the sea and others had fresh-water lakes, today comprises of sand dunes, sabkahs (salt flats), and sand sheets

Though sand blows off the surface, the sand dunes don’t drift. The essential shape of the major sand dunes remains intact. This is probably due to the moisture leaching up into the base of the dunes from the surrounding sabkahs.

The Rub’ al-Khali, one of the driest regions in the world, is virtually uninhabited and largely unexplored.

The sand gets its reddish-orange colour due to the presence of iron oxides and feldspar

The recurring patterns in the sand are created by the Sandfish, a lizard, having a remarkable ability to move in the desert sand in a swimming-like fashion. The smooth skin of the sandfish has very little friction with the sand allowing it to move at a very fast speed. 

Sand Grass, which can be found in the sands of Rub’ al-Khali can take in water from the moisture in the early morning air allowing it to survive in this arid climate

Bean Caper, a plant usually found in the flats between the dunes has roots that go three to five meters underground to find water. The small leaves contain salt water, are a favourite food of the camel and can help you survive in the desert if you are lost without food and water  

Today, people do guided walks in the areas, but the first non-locals to explore the area were Britishers, Bertram Thomas and St. John Philby in the early 1930s

The Empty Quarter has been used as a setting by writers in their books; as a location for movies by producers; and also finds itself being used as a setting in video games like Playstation!

The year 2019-20 saw unprecedented rains in parts of the Rab’ al-Khali, after more than two decades, leading to formation of temporary lakes and sprouting of many more greens than usual, in the desert sands

The Empty Quarter may be largely uninhabited with the exception of some nomadic tribes around its edges, but discovery of large amounts of oil in this area has led to hectic activity in search of the liquid gold

The Rub al-Khali contains about half as much sand as the Sahara, despite being only around 1/15^th its size. This is due to large parts of the Sahara being made up of rocks and gravel