I like these two Galway sites
http://www.megalithomania.com/show/image/4283
http://www.megalithomania.com/show/image/4276
Although the first one is on a cliff-top, not the beach, as is
http://www.megalithomania.com/show/image/6636
And this one's got a certain something when you're there ... just 150m from the Atlantic coast and the wind let's you know it!