Set on its towering rock above Tremadog Bay, Harlech is the most dramatically-sited of all the castles raised by Edward I to overawe Wales. Designed by the brilliant castle-architect James of St George, it was raised between 1283 1290 by an army of craftsment and labourers: at one stage nearly a thousand men were hard at work here. They came from far and wide - masons from Savoy on the borders of France and Italy and from Ireland, carpenters and blacksmiths from all over England, William the Plumber of Lichfield, Madog the Welshman and his mates and Eynon the Shropshire hod-carrier.

Between them they created a seemingly impregnable fortress, naturally protected on three sides by cliffs and defended by concentric lines of mutually-supporting fortifications. Attackers who reached the great gatehouse - a stronghold in itself - must penetrate its devilish complex of gates, portcullises and loopholes.

No wonder Harlech became the "castle of lost causes", where diehard garrisons could defy thousands of besieges. It was the final refuge of Owain Glyndwr's Welsh patriots and later of Welsh Lancastrians - the "Men of Harlech" of the famous song - Harlech was the very last Royalist stronghold to fall during the Civil War.

Despite the assaults of war and time, this masterpiece of medieval fortification has survived remarkably intact. With its panoramic backdrop of the Snowdonian mountains, Harlech has proved irresistable to painters, photographers and visitors, and is now a World Heritage Listed Site.