Cahir's awesome castle enjoys a river-island site with moat, massive walls, turrets and keep, stalwart defences, mullioned windows, vast fireplaces and dungeons. Founded by Conor O'Brien in 1142, it's one of Ireland's largest castles, passing to the Butler family in 1375. In 1599 the Earl of Essex shattered its walls with cannon fire, an event explained with a large model. With a huge set of antlers pinned to its white walls, the Banqueting Hall is an impressive sight; you can also climb the Keep .
The castle eventually surrendered to Cromwell in 1650 without a struggle; its future usefulness may have discouraged the usual Cromwellian 'deconstruction' – it is largely intact and still formidable. It was restored in the 1840s and again in the 1960s when it came under state ownership.
A 15-minute audiovisual presentation puts Cahir in context with other Irish castles. The buildings within the castle are sparsely furnished, although there are good displays, including an exhibition on 'Women in Medieval Ireland'. There are frequent guided tours.