Skellig Michael was certainly the highlight of our trip, but we also enjoyed visiting the Dingle Peninsula and Bru na Boinne.

• Glendalough - founded by St. Kevin in the 6th Century, it was destroyed by the English in 1398 and abandoned in 1539. The surroundings of this set of monastic ruins are quite pretty and we walked around the area for a couple of hours.
• Rock of Cashel - the castle of the Munster kings, the oldest building (the round tower) dates from 1100 AD. We spent half a day walking around the site before heading to Portmagee.
• Torc Waterfall - A scenic waterfall in Killarney National Park.
• Dingle Peninsula - Dingle is a great little town, and the Slea Head drive is very pretty. In fact, we drove around the peninsula twice, the second time because we wanted to see the sights in better light. There are some interesting sites to visit on the drive, including the Gallarus Oratory, which is an early Christian church built between the 6th and 9th century; there is free public parking right next to the site, so you don't have to pay to go through the commercial buildings on the main road.
• Cliffs of Moher - pretty cliffs of shale and sandstone off the Irish coast. There are fences and barriers preventing visitors from standing at the edge, which the views looking down would have been quite nice.
• The Burren - "rocky place", it's a 10 square mile limestone plateau where the surface stone has partially eroded, leaving cracks where vegetation grows. It is a rather unusual sight. We also visited Poulnabrone Dolmen in the Burren, which is a portal tomb from between 4200 to 2900 BC.
• Kinvara - we stayed the night in Kinvara as a stop before driving back to the east part of Ireland. We enjoyed our stay at Cois Cuain B&B and also the live music in the nearby pub recommended by Mary, who runs Cois Cuain.
• Bru na Boinne - contains neolithic passage tombs. We only managed to visit Newgrange, which is a passage tomb built between 3300 to 3900 BC, which predates the Giza pyramids by around 500 years and Stonehenge by around 1000 years. We got to enter Newgrange and examine the spiral carvings in the center of the tomb and be impressed by the amount of work the neolithic people put into building it. Unfortunately, we did not visit Knowth, which would probably have been quite nice too.
• Trim - we stayed in Trim to avoid driving into Dublin, and it turned out to be a very pleasant experience. We walked around the green area next to Trim Castle with the Yellow Steeple around sunset, which was quite scenic. The day before flying home, we took a bus into Dublin to walk around central Dublin, as well as visit the National Museum of Archaelogy and History, before returning to Trim to visit Trim Castle.