Overlooking the beautiful Killarney Lakes, Aghadoe Cathedral refers to a stone structure built sometime in the 11th century, although some say the site could have served as a church as early as the 7th century when he founded the monastery of St. Finian the Leper ( Finian the Leper). Two important artifacts were discovered in Agado, the Ogam stones, which indicate the importance of the church from the 7th century.