The Castle is constructed upon the end of a ridge of Chalk extending from the South Downs, with a natural escarpment upon the east and south. It is an excellent example of masonry superseding earthwork defences without obliterating their original lines. The position is such as to suggest a prehistoric camp of the promontory type. The chief original defence was the great moated mount, which is over 200 feet in diameter; on the south side the height from the summit to the bottom of the ditch is 70 feet, being altogether but a little smaller than Windsor. Like the latter it possesses two baileys, occupying over 5 acres in extent, and together forming an oblong enclosure. The mount stands near the centre of the western side upon the enceinte, the ditch forming part of the outer ditch of the Castle in one place. This outer fosse has been much strengthened by artificial means, but is in many places natural. [Illustration: ARUNDEL CASTLE, SUSSEX.] Upon the motte a Shell Keep was erected in the late Norman Period; it is about 20 feet high, with walls nearly 10 feet thick, and is almost 70 feet in diameter. The walls are faced with Caen stone covering a core of Sussex stone and Chalk. The barbican, called the Bevis Tower, and a portion of the great gatehouse, were built in 1295 by Richard Fitz-Alan, who also erected four towers at equal distances round the enceinte. After the last siege the place remained a heap of ruins for many years, but about 1786 the tenth Duke of Norfolk began to rebuild it, and expended vast sums upon the fabric. The result was the practical re-erection of the present magnificent structure, a typical example of the stately homes of England, and an appropriate dwelling-place for our premier Duke, who has in comparatively recent years erected a sumptuous Cathedral as a fitting companion to the ancient baronial Castle. _Carisbrooke._--Carisbrooke stands upon a site which was undoubtedly a fortress occupied by the Jutes, who conquered the island; William Fitz-Osborne, Earl of Hereford, obtained possession from the Conqueror and reared a motte and bailey castle there. His son, who was imprisoned for life, forfeited the estates, which came into possession of Richard de Redvers, whose heir became Earl of Devon. Piers Gaveston held the Castle in the fourteenth century, and also the Earl of Rutland, son of Edmund of Langley; it was in the occupation of a number of persons subsequently but fell to the Crown in the fifteenth century. It is intimately associated with the unfortunate Charles I., who made three distinct attempts to escape from its confinement. The mound of the Norman Castle was enclosed by a Shell Keep by Richard de Redvers; it is an irregular polygon of eleven faces and sixty feet in diameter, the walls being of enormous strength and thickness. Entrance is gained by a long flight of steps leading to a passage defended by a portcullis and double gates. The Keep encloses one of the two Castle wells.