Though I wish I had the original poster’s PHOTO MANIPULATION talents, and though I wish there really was a very cool castle like that balanced on a rock island, it’s not true. Not in Ireland, not really a castle on top. HOWEVER, this rock island is still very cool anyway! And the island itself is real, in Thailand. I researched to get to the truth of the matter (because of my curious nature), and here is the Wikipedia entry for the real rock island (now called James Bond Island!): http://en.wikipedia.org/wiki/Khao_Phing_Kan
UPDATE 11/22/13: Thank you very much to Eiskje who commented with a YouTube video of the photo manipulation artist (Jan Oliehoek) showing his effects in a video, including this very castle on an island, as well as several other special photo effects. I am grateful to the commenter for sharing this info as I was unable to credit the artist originally since I could find no reference for it.