Guildford Castle, of which the keep was always the most prominent, and is now the chief remaining, feature, is in position, age, structure, and dimensions, a very remarkable fortress. It is true, indeed, that though of great age, neither the town nor the castle have played any great part in English history. The town was never walled; the castle never stood a siege. No considerable battle was ever witnessed from its towers; no parliament or great council was ever held within its hall. Though always a royal manor, and long maintained as a royal residence, it was used also as a prison, and is but rarely mentioned, either in the records or by the chroniclers. The castle was not garrisoned in the great civil war, and so escaped being dismantled and blown up by either king or parliament. Its state of decay is due to the effects of time, powerfully aided by the local greed for building materials. Nevertheless, though wanting in many of the points of interest often attaching to English military buildings, Guildford Castle has certain peculiarities of its own not unworthy of notice, and which it is the object of this notice to set forth and explain. The great chalk range which forms the bulwark of London and the southern limit of the vale of the Thames, from its mouth to the border of Hampshire, is contracted towards the west into a narrow but elevated ridge, which extends from Reigate nearly to Farnham and, resting upon the firestone and gault of the Weald of Kent and Surrey, supports the clay and gravels of the London basin. This ridge, generally unbroken, is traversed by two well-known gorges about twelve miles apart, of which the eastern is occupied by the Mole at Dorking and Mickleham, and the western by “The chalkey Wey, that rolls a milky wave.” The Wey, the tributaries of which rise widely over much of Surrey and the eastern part of Hampshire, is, where it cleaves the chalk, a considerable stream, much less milky than in the days, or rather in the verse, of Pope; and twelve miles below the pass it falls into the Thames at Weybridge.