It must not be imagined that the castle-building energies of Edward I. were entirely expended upon the grand examples of his work found in North Wales, on the contrary there are many buildings to be discovered where his handiwork, or that of contemporary barons, is a prominent feature. A tendency appears to have manifested itself at that period to alter existing castles of a previous type so that they conformed in some way to the concentric ideal, and Pevensey, Chepstow, and Corfe are cases in point. In addition to Caerphilly in Glamorganshire there are many other structures in South Wales showing a very high ideal of castellation, indeed that portion of the Principality has been termed the "Land of Castles," and the appellation is by no means undeserved. There is hardly a prominent position upon the coast, or a suitable site inland, but what has been seized upon at some period to erect a position of defence. _Pembroke Castle_, with the town walls supporting it, is perhaps the most important pile to be found in this district; it embodies additions of varying dates in its massive walls and towers. The great gatehouse and circular Norman Keep are undoubtedly its chief attractions at the present day when, although shattered by powder after Cromwell's capture by means of starvation, and much subsequent spoliation, it presents one of the most imposing aspects to be found in the kingdom. _Carew Castle_ is deservedly celebrated for picturesqueness and affords an illustration of the use of the angle-spur at the foot of drum towers as a preventive against mining. _Cilgerran Castle_ occupies a position which is probably unparalleled in South Wales. It approaches very closely to the Edwardian type, but the area chosen has not entirely dominated the plan; it once possessed an inner and outer bailey with a great portcullised gatehouse and massive cylindrical towers, two of which still stand. Pembrokeshire is essentially the centre of the castle-land of Wales, for besides those mentioned there are Manorbier, Lamphey, Narberth, Haverfordwest, Llawhaddon, Roche and many others, most of them exhibiting traces of Edwardian influence based upon Norman work. In the upper valley of the Wye the efficiency of castles was of great importance, inasmuch as they guarded one of the great lines of incursion from the heart of Wales into the Marches; here Edwardian additions may be seen at Builth where a donjon was placed upon a motte which had already been encircled by a Shell Keep, while a circular rampart surrounding the whole bailey made a very presentable representation of the concentric ideal. At Bronllys, farther to the south, a cylindrical tower was the chief addition, while at Tretower, still farther south near Crickhowell, a Shell Keep appears to have been inserted within the remains of a previous Rectangular Keep defending the motte.