I was really looking forward to seeing this as the story of Grace O'Malley is a fascinating one. I was pleased with the condition of the structure....it's a ruin, but a well-preserved one. Disappointing was the rubbish inside... a distinctly post-medieval oil drum!
The Cistercian Abbey dates from the mid 15th century and inside is a tomb said to be that of the 'Pirate Queen' Grace O'Malley. There are also rare medieval wall paintings. The graveyard is quite interesting with, not surprisingly, an abundance of O'Malleys buried there. I was also surprised and moved to see a memorial to the crew of a Canadian WW2 plane that went down off the coast.
Given the lack of cars (there are few, but not a lot) and the many little lanes criss-crossing the island it's a great place for walking. We got a leaflet on the ferry with few suggested routes ranging from a one hour walk around the harbour area to a 5+ hrs hike taking in the whole island, including the summit of Knockmore. We chose the loop around Knocknaveen. The walking was very easy, taking in the beautiful scenery and the old abbey.
The ferry to Clare Island leaves from Roonagh Quay on the mainland. There are two different companies operating from here, with their ticket offices next to each other. We went with the one who greeted us first, Clare Island Ferry Co., although both departed at the same time and for the same price (15 euros return).
The outbound trip was onboard the 'Very Likely', a small boat carrying only a dozen or so passengers. It was full so we had to sit inside the cabin. Too bad, as I would have enjoyed the scenery. The return trip was onboard the much bigger 'Pirate Queen'. It was great to sit on the upper deck, although there is the option of sitting inside if you want.