Hvitserkur...a petrified troll?

Sadly our little holiday in the North of Iceland is over, and we had to drive back today. On the way we stopped at 3 different sights we had not seen before, an amazing waterfall that had 5 different falls, a stone basalt wall that seemed to have surrounded some fortress and lastly a 15 metre high stone formation in the sea that resembles a huge 4 legged animal. On the picture I took, one can see 2 people who were trying to get a closer look at it, they look like really tiny.