English: Salisbury Crags, Arthur's Seat It is scarcely credible from a modern perspective that an estimated 55,000 tons of rock were removed from the crags before quarrying, started in the late 1780s, was halted in the early 19th century. The pioneering conservationist, Henry, Lord Cockburn, wrote in 1840, "By 1816 the cliff had been so quarried away that what used to be the footpath was, in many places, at least 100 feet wide; and if this work had been allowed to go on for a few years more, the whole face of the rock would have disappeared. This would have implied the obliteration of some of the strata, which all Edinburgh ought to have revered as Hutton's local evidence of the Theory of the Earth, and one of the most peculiar features of our scenery." http://www.geo.ed.ac.uk/scotgaz/features/featurefirst250.html