Mid-summer highs in excess of 45 C are common in the central sand sea.

Actually, engineers generally seek ancient river channels now buried by the sand seas.

Within sand seas in a given area, the dunes tend to be of a single type.

Somewhere between those contorted ridges was a track through to the sand sea and the Fortress of the Rock.

The sand sea stretches out to the east, while the oasis, its river and palm groves are spread out before you to the west.

The three sand seas, which contain dunes up to 512 meters in height, cover approximately one quarter of the region.

When these are extensive, they are known as sand seas or ergs.

Rand's eyes were still roaming the sand sea, out to the limiting line of the horizon and then coming back again.

Dome dunes are rare and occur at the far upwind margins of sand seas.

It was not, however, a sand sea throughout that entire period.