They were not unbroken walls of rock, but were built sectionally, in crags like gigantic buildings, along the two sides of their street. Deep alleys, fifty feet across, divided the crags, whose planes were smoothed by the weather into huge apses and bays, and enriched with surface fretting and fracture, like design. Caverns high up on the precipice were round like windows: others near the foot gaped like doors. Dark stains ran down the shadowed front for hundreds of feet, like accidents of use. The cliffs were striated vertically, in their granular rock; whose main order stood on two hundred feet of broken stone deeper in colour and harder in texture. This plinth did not, like the sandstone, hang in folds like cloth; but chipped itself into loose courses of scree, horizontal as the footings of a wall.