Old Leighlin is most noted for it’s Cathedral. Early in the seventh century St. Gobban founded a monastery at Old Leighlin where in 630 A.D. a Synod was held to deliberate on the time for the holding of Easter.
The Roman & the Celtic churches followed different systems. The Synod decided in favour of the Roman system and St. Laserian, who succeeded Gobban as abbot in 632A.D. was influential in this matter.
This Cathedral was once the home of 1500 monks. Today, there are only a few remains, including Saint Laserians Cross.