A little late to the party, but I offer the following observations (can't solve it yet

)
I don't think it is Orkney (Flotta, Hoxa or Lyness) - lots of pictures are available showing those areas on
http://www.geograph.org.uk/ - always worth a look before jumping in with any guesses. Also, the field boundaries on Orkney are not solid as shown in the headland in the background, they are generally open wire fences.
The path on the right would appear to be at the same level as the top of the bridge, which has a platform lower down and is attached to the top by a vertical pair of wires on either side of the walkway. So is the path actually a covering/awning over a path on the right hand side which we cannot see? If so, why has it been covered? A disguise? And does it lead to a structure on the rock in the middle of the picture which faces the headland in the background, but is set down low below the 'skyline' of the rock? Although it would have to be a pretty small building - there's not a lot of surface area there. It also looks like a wall on the right abutting the path/awning, with at least two quite sharp angles in it. Pity there isn't more visible on that side.
I don't think that the rock is yet an island - it is still connected at sea level, but the fact that there is a bridge would seem to indicate that there was something on the rock that someone wanted to reach and maybe not just a view.
The rock is probably grey, maybe a shale like rock.
I could be hopelessly wrong, but it might stimulate some further useful discussion .

Nell