Robert Alexander Wahab, 1911 Encyclopædia Britannica (1911)
“ According to him, a long desert march leads from Madnab to Zulfa the first settlement in Sudēr, where the land rises steadily to the high calcareous tableland of J. Tuwēk. The entire plateau is intersected by a maze of valleys, generally with steep banks, as if artificially cut out of the limestone. In these countless hollows is concentrated the fertility and population of Nejd; gardens and houses, cultivation and villages lie hidden from view among the depths while one journeys over the dry flats, till one comes suddenly on a mass of emerald green beneath. ”
