But the sole square tower with its corner turrets remains, even in the fourteenth century, the type of the castle keep. The chateau of Vincennes, built by Charles V., is an admirable example of the kind. II It was not easy to enter the castle keep. It stood encircled by a strongly fortified enclosure, isolated by moat or precipice, and defended, not only by outworks of palisading, but by a barbican and several smaller towers. Having run the gauntlet of all this, having passed down the narrow winding path between the palisades, the visitor arrived at the moat, and blew a horn hung there for the purpose. After parley with porter and watchman, the drawbridge was let down; and after further parley, perchance, the great gate may have swung back on its hinges. In this case, the stranger found himself in a long hollow archway, protected by a series of portcullises, with a perforated roof, through which boiling pitch, molten lead, Greek fire, or simple scalding water could be poured down from an upper chamber. In time of peace, however, the visitor passed unscathed through the gate into a vast courtyard enclosed by huge battlemented walls or towers; a courtyard that is almost a village, for it contains the church, the knights’ quarters, the squires’ house, the lodgings for pages and servants, the barracks, the cottages of the artisans and labourers on the estate, the bake-house, the kitchen, the walled and gated fish-pond, the fountain, the washing-place, the stables, the barns, etc. A second gate, a second portcullis, lead to a smaller court, where--huge, swart, and sombre--towers the keep. It is immense, it is impregnable, and always opposite to the weakest point of the defence, with a postern of its own leading to the orchard, and a subterranean way into the open country. Those who have admired the black majesty of Loches will admit the grandeur of the mediæval keep.