776 – Round Tower, Clondalkin, Co. Dublin
Well preserved 8th century round tower that acts as a focal point for the area. Acknowledged as one of the oldest and best preserved in the country, it is 84 feet high and has its original conical cap. The foundation of the first monastery is attributed to St. Cronan, otherwise called Mo-Chua, who lived possibly in the 6th century. The monastery is first mentioned in 776. It was plundered by the Vikings in 832.