From my trip to Ireland in fall 2007.
We actually went to Limerick (in southwestern Ireland) before Cashel and near the end of the day. Which means we hit some rush hour traffic. Times for viewing castles, museums and other heritage sites change in October and we had brochures that gave different closure times. So we raced to King John’s castle in Limerick and then found out we were good and had an extra hour.
This was indeed an actual military castle (as opposed to Cashel’s ecclesiastical nature). King John did use it for some of his wars and though it was very castle like, (like a fantasy or Disney version) it was also very sterile in looks and overall not as interesting to me as the gothic castles with their sculptural aspects and arches.
Because the castle was an English stronghold for a king, it was known as English town with Irish town being across the water of the River Shannon. The castle itself was completed in 1200, making it a medieval fortification that was kept upgraded from many centuries. It was on King’s Island and the fortification was undermined in the 1700s in one of five battles.
There was a museum part to the castle below but I don’t remember much about it and like I said, overall the castle was so cleanly laid out as a rectangle that it was boring on some levels. The walls of course were extremely thick, some two feet or so. It took us an hour to stroll leisurely through the grounds and that was enough for King John’s castle. We left Limerick and moved on as that seemed to be the town’s highlight.