Hi Bud,
Thanks for your kind words.
I took this shot using a spirit bubble on the hot shoe and the internal incline-ometer (which is quite good) on my 5D mkIII. There's a big wave on the horizon. I think it is distorting the horizon line making it look slightly off. The castle walls aren't vertical either, the most vertical one is the far left, but the towers to the right lean out a bit, which I'm guessing are the ravages of time. So I usually use a bubble to get my levels in this spot.
There was a strong side light, but thankfully my 24-70L has this huge hood which kept the flare at bay. Something with is a pity that isn't carried over to the new mk II version!