"Please note that this is a very busy site and visitors may experience a delay during the summer months." Guidebook
Since this isn't summer and the wind was blowing off the river Shannon at about 25 knots at 35 degF, crowds were expectantly sparse. And despite all the things that one could see here, the gusting winds lifting you off the ground discouraged extensive exploration.
The site has a long history, having been founded in the 6th Century. It was constantly overrun and sacked by just about everyone including the Vikings, its occupants killed, and its buildings destroyed many times. Because of its location at a junction of the Shannon and trade routes, it eventually became a fort as well as a monastery and was actually stable for a while, until its eventual abandonment around 1100 AD.
It has two wrecked cathedrals -- not the kind that immediately comes to mind, but medium sized stone buildings. Very little fancy stone work, this isn't the Vatican by any stretch of the imagination.
In addition there are several small churches that look suspiciously like small stone buildings, and two fine examples of Irish round towers.
A main source of fame is the fact that the site contains 3 stone "high crosses", some of the few that are still in existence. They are intricately carved, and are of historical and artistic significance -- information that is too complex to get into here.
This Irish weather is something. There had to have been some pretty important reasons to even attempt to live here with nothing but burning peat to keep one warm in the winter. We've been fortunate that we've had alternating good and rainy days. All rain would have been too much.