Here on Aghadoe Hill stand the ruins of the 12th century Aghadoe Church and Round Tower. There was a monastery on the site since the 7th century, however, founded by St Finian Lobhar, and no wonder as the views are sublime and perfect for a life of contemplation. There are lakes and at night the town lights of Killarney twinkle, alongside the flood lights of Ross Castle in the distance, although that is a bit more recent dating from the 15th century! To appreciate the landscape, you'll find a few benches nearby so bring a picnic.
Although ruined, there is still plenty to see of interest at Aghadoe Church. The Romanesque door is well-preserved, there is a carved crucifixion scene on another sandstone block, two ca rved faces on the eastern window, and an Ogham Stone - carved writings in the ancient Celtic language. Not much is left of the Round Tower. It is really just a small stump of the sandstone building standing in an old cemetery.
Not far north-west of Killarney (2 miles / 3.2 km), the ruined church and tower are close to the Aghadoe Heights Hotel. You can park in a carpark just before the hotel and walk across to the church.