The first stone-built Norman fortification in Wales, Chepstow Castle retains more of its original masonry than almost any other castle in the UK.
Recycled Roman bricks are still visible in the walls of the great hall. Situated on top of the limestone cliffs guarding the Welsh bank of the River Wye, work started on the site just one year after the Battle of Hastings - at a time when almost every other Norman fortress was a temporary timber affair.
But Chepstow's strategic position as a base from which to subdue the Welsh made the investment in stone worthwhile.
Only a few decades later it became the stronghold of Richard Strongbow, who led one of the first Welsh/Norman invasions of Ireland and conquered Leinster.
During the 12th and 13th centuries the castle was massively fortified and expanded, but it played no strategic role until the Civil War four centuries later. Twice besieged by Oliver Cromwell, his final attack breached the walls with cannon.
Repairs were carried out and a garrison remained, but the castle served as little more than a political prison. The garrison left for the last time in 1690 and the castle was left to decay slowly for more than 250 years, before it passed into the care of the state in 1953.