http://maps.google.com/maps?f=q&source=s_q&hl=en&...
It does look quite artificial compared to the surrounding ocean floor.
Here's Google's official denial:
http://www.google.com/hostednews/ukpress/article/ALeqM5h3fST...
http://www.telegraph.co.uk/scienceandtechnology/technology/g...
I, for one, welcome our new undersea giant overlords.
P.S.: Gmaps is full of artifacts like that. Here's another one, bigger than Ireland:
http://maps.google.com/?ie=UTF8&t=h&ll=54.188155,-12...
http://maps.google.com/maps?f=q&source=s_q&hl=en&...
It does look quite artificial compared to the surrounding ocean floor.