The _Castle of Harlech_ approaches the concentric form so far as its position will permit, but the bold rocky promontory upon which it stands was too irregular for the complete ideal, and consequently the Castle was adapted to the site. It is practically an oblong with massive circular buttress towers at the four angles; two others defend the gateway and two smaller ones are on either side of the barbican entrance. Small watch-towers, corbelled at the summits upon false machicolations, are adjacent to the larger. The barbican lies upon the eastern side of the fortress, and was only accessible by a steep and narrow entrance after a dry ditch had been crossed. Harlech and Kidwelly are similar in not being purely concentric; each have short fronts of wall and the defences of two of the baileys are united, thus only two lines of resistance are interposed. Neither possess a donjon, the two inner wards being the last resort of the garrison. The inaccessibility of this massive pile, perched 200 feet above the adjacent sea and producing a strangely impressive effect by reason of its grim vastness, has been repeatedly tested since its walls were first raised. Owen Glendower beat in vain against its impregnable strength and lost Mortimer, his son-in-law, before its walls. In the Wars of the Roses, when the soul-stirring "March of the Men of Harlech" was penned, the Castle was summoned to surrender by the Yorkists, but the Constable of the time, a doughty Welshman, held out for the Lancastrian cause and made a most protracted resistance in the campaign of 1474, Harlech being the last fortress to surrender in that great struggle. In the Civil War it maintained its reputation, but was finally delivered up to Cromwell's brother-in-law. _Conway Castle_, one of the most impressive and majestic of medieval fortresses in Britain, is situated in a romantic and picturesque spot at the mouth of the river Conway. It presents a perfect ideal of a fortress and a fortified town, the massive accompanying walls of the latter forming an integral portion of the defence as a whole. The town walls are over a mile in length and are in a singularly good state of preservation; there are twenty-one towers, arranged at regular intervals along this enceinte, and four gates, over one of which is a row of machicoulis, twelve in number, projecting from the upper part of the wall. It was also protected by a dry ditch and with drawbridges placed before the gateways. [Illustration: LEEDS CASTLE, KENT.]