Arthur's Seat, a well-known lion-shaped hill immediately east of Edinburgh, rising to a height of 822 feet above sea-level. The ascent is easy, and the prospect from the top unrivalled. Arthur's Seat is supposed to derive its name from the British king. When the hill received this appellation is not known; but at the close of the 15th century, the poet Kennedy mentions 'Arthur Sate or ony higher hill.'
The hill consists partly of aqueous sedimentary rocks, and partly of volcanic rocks. The aqueous strata are of carboniferous age, and are overlaid by a succession of beds of basalt and porphyrite, with intercalated beds of fragmental volcanic materials. These bedded rocks are traversed by irregular sheets of dolerite and basalt, which form the mural cliffs of Salisbury Crags, Samson's Ribs, &c. The bedded igneous rocks point to subaqueous volcanic action in carboniferous times. At some subsequent period—long after the carboniferous strata had been elevated, folded, fractured, and much denuded—volcanic action again broke out on the site of Arthur's Seat. The rocks ejected at this later period are represented by the coarse volcanic agglomerate and overlying dolerite, &c. of the Lion's Haunch, and the basalt of the summit of the hill—this latter occupying the pipe or throat of the younger volcano.