Editing Geography of Saudi Arabia (section)

=== Eastern Arabia ===
East of the Ad Dahna lies the As Summen Plateau, about 120 kilometers wide and dropping in elevation from about 400 meters in the west to about 240 meters in the east. The area is generally barren, with a highly eroded surface of ancient river gorges and isolated buttes.

Farther east the terrain changes abruptly to the flat lowlands of the coastal plain. This area, about sixty kilometers wide, is generally featureless and covered with gravel or sand. In the north is the Ad Dibdibah graveled plain and in the south the 'Al Jafurah sand desert, which reaches the gulf near Dhahran and merges with the Rub al Khali at its southern end. The coast is extremely irregular, merging sandy plains, marshes, and salt flats almost imperceptibly with the sea. As a result, the land surface is unstable; in places water rises almost to the surface, and the sea is shallow, with shoals and reefs extending far offshore. Only the construction of long [[Mole (architecture)|moles]] at Ras Tanura has opened the Saudi coast on the gulf to seagoing tankers.

Eastern Arabia is sometimes called [[Al-Ahsa Oasis|'Al-Hasa]] or 'Al Ahsa after the great oasis, one of the more fertile areas of the country. 'Al-Hasa, the largest oasis in the country, actually comprises two neighbouring oases, including the town of Al-[[Hofuf]].