11. In the crevices or ravines themselves, the waters having cleared away masses of this loose rubbish, have laid bare whole sides of walls of solid brick-work, sometimes even a piece of a human head or limb, or a corner of sculptured stone-slab, always of colossal size and bold, striking execution. All this tells its own tale and the conclusion is self-apparent: that these elevations are not natural hillocks or knolls, but artificial mounds, heaps of earth and building materials which have been at some time placed there by men, then, collapsing and crumbling to rubbish from neglect, have concealed within their ample sides all that remains of those ancient structures and works of art, clothed themselves in verdure, and deceitfully assumed all the outward signs of natural hills. 12. The Arabs never thought of exploring these curious heaps. Mohammedan nations, as a rule, take little interest in relics of antiquity; moreover they are very superstitious, and, as their religious law strictly forbids them to represent the human form either in painting or sculpture lest such reproduction might lead ignorant and misguided people back to the abominations of idolatry, so they look on relics of ancient statuary with suspicion amounting to fear and connect them with magic and witchcraft. It is, therefore, with awe not devoid of horror that they tell travellers that the mounds contain underground passages which are haunted not only by wild beasts, but by evil spirits--for have not sometimes strange figures carved in stone been dimly perceived in the crevices? Better instructed foreigners have long ago assumed that within these mounds must be entombed whatever ruins may be preserved of the great cities of yore. Their number formed no objection, for it was well known how populous the valley had been in the days of its splendor, and that, besides several famous cities, it could boast no end of smaller ones, often separated from each other by a distance of only a few miles. The long low mounds were rightly supposed to represent the ancient walls, and the higher and vaster ones to have been the site of the palaces and temples. The Arabs, though utterly ignorant of history of any kind, have preserved in their religion some traditions from the Bible, and so it happens that out of these wrecks of ages some biblical names still survive. Almost everything of which they do not know the origin, they ascribe to Nimrod; and the smaller of the two mounds opposite Mosul, which mark the spot where Nineveh itself once stood, they call "Jonah's Mound," and stoutly believe the mosque which crowns it, surrounded by a comparatively prosperous village, to contain the tomb of Jonah himself, the prophet who was sent to rebuke and warn the wicked city. As the Mohammedans honor the Hebrew prophets, the whole mound is sacred in their eyes in consequence.