Pretty much sooc, I thought I had levelled it, and cropped it slightly.
Not very good at pp yet, will try again tomorrow.
If this was part of a lesson you obviously could not choose the time of shooting but earlier in the evening when there is some light in the sky is best for this kind of thing.
To get the camera level at the time of taking use a spirit level if you intend to shoot landscape or architecture though if you are using a Nikon D750 I would expect it has a built in level
http://www.amazon.co.uk/dp/B00A3SPO...m=A3P5ROKL5A1OLE&pf_rd_r=1ABZFD5V4STYBM4CNSAK
It is hard to tell with the shot but the crop you made has left a black edge on the left and top right of the shot.
To load from Flickr you copy the BB code and past that into the post.
Seeing as you have image editing ticked as a yes - quick edit with straightening on the middle pole for vertical. Did a quick tone and curves adjustment. Not much to work with as its such a small file size.
One thing I picked up years ago, horizontals are not necessarily horizontal depending on the angle you look at them but verticals should always be vertical (unless they are converging).