This is kind of amazing all by itself:
> The harrah near Madinah has been active for more than two million years, explains Mohammed-Rashad Moufti, a consultant to the Saudi Geological Survey (SGS)... Mohammed-Rashad Moufti holds Saudi Arabia’s first—and so far only—doctoral degree in volcanology. He has devoted 20 years to studying and promoting awareness of the lava field near Madinah, which is known as Harrat Rahat.
“We removed again, and when we encamped, I looked round from a rising ground, and numbered forty crater hills within our horizon; I went out to visit the nighest of them. To go a mile’s way is weariness, over the sharp lava field and beds of wild vulcanic blocks and stones. I passed in haste, before any friendly person could recall me; so I came to a cone and crater of the smallest here seen, 300 feet in height, of erupted matter, pumice and light rusty cinders, with many sharp ledges of lava. The hill-side was guttered down by the few yearly showers in long ages. I climbed and entered the crater. Within were sharp walls of slaggy lava, the further part broken down—that was before the bore of out-flowing lavas—and encrusted by the fiery blast of the eruption. Upon the flanks of that hill, I found a block of red granite, cast up from the head of some Plutonic vein, in the deep of the mountain.”
CHARLES M. DOUGHTY TRAVELS IN ARABIA DESERTA (BONI & LIVERIGHT, 1921)
Arab legends have it that many tribes were wiped out by lava flows as they attempted to escape the Peninsula during a distant time of catastrophe. The Amelekites followed a long, dark cloud which led them to Egypt, which they looted and destroyed, taking the defenceless Egyptians captive.
Harrat Rahat Elevation 1,744 m (5,722 ft)
Location Saudi Arabia
Coordinates 23°5’0” N 39°47’0” E
Geology Type Volcanic field
Last eruption June to July 1256 Harrat Rahat is a volcanic lava field in Saudi Arabia. In 1256 AD a 0.5 cu km lava flow erupted from six aligned scoria cones and traveled 23 km to within 4 km of the holy city of Medina: this was its last eruption. There were earlier eruptions. It is the biggest lava field in Saudi Arabia. Nearby is the Al Wahbah crater.
http://en.wikipedia.org/wiki/Harrat_Rahat