Monday’s Daily Jigsaw Puzzle

(The latest Animated jigsaw puzzle is obviously popular. It’s been downloaded over 8,000 times in two days. Check it out if you haven’t yet. Page 18 of the Animated Jigsaw Puzzles section.)
It’s a Monday, and no matter how much you are expecting it, Monday’s are always a surprise. So today’s jigsaw puzzle is a surprise, or mystery, jigsaw puzzle.
It’s a photograph of the Carrowmore Megalithic Cemetery in Ireland. I had no idea these things existed until I found the photograph.
(OK, so that took part of the mystery away. You still don’t get a preview of the jigsaw puzzle.)

Easy   Medium   Hard   Tough