On satellite images, this desert shows a pattern of long sand ridges running in a roughly north-south direction.

However, despite the apparent uniformity, the Great Sand Sea has two large areas with different types of megadunes.

The dunes of the Great Sand Sea cover about 10% of the total area of the Egyptian Western Desert.

Siwa is an oasis located in Egypt, about 50 km (30 mi) east of the Libyan border, in the eastern part of the Great Sand Sea or Egyptian Sand Sea.

Although well-known to the Tuareg and traders who traveled with caravans across the Sahara, Friedrich Gerhard Rohlfs was the first European to document the Great Sand Sea.