I would fill in the opening if you decide to hang the TV over the fireplace. I feel that doing so would go well with your home. However, before going too far it would be helpful to see a floor plan or some additional photos of all of the walls in the space.

It would be better than where it is. Hang low resting on top of mantel. Otherwise gets too high. Add panels to windows.

It won't cover that whole opening though. No matter how you hang it. Maybe put moulding around then paint firepl. A darker shade of walls.

Stone it if you can! Perfect wall for it. A natural stone that is a veneer thickness of about 2" will keep the cost down but still give you Real stone appeal. You should get some foam board, make a template the size of your t.v. And tack it up first. You may find it is uncomfortable to view it when mounted that high. If not at least you can easily determine perfect mounting ht.

That's the only wall in room, left side is windows, right sliding glass door, back up to kitchen

I would hang the TV over the fireplace. That's where we have ours.

ladee900 - thank you for posting additional photos of the space. They reaffirm my earlier comment to hang the TV over the fireplace.

Thanks for comments, now what size tv, entire wall is only 70, opening is 35. I wanted at least a 50-60 inch. Opening has outlets inside and cable, do I close it in? Where does equipment such as direct tv receiver and DVD player go?

Fireplace doesn't have a mantel, and not sure if I can paint, it is done type if marble or granite. Wanted to paint room dark but kitchen and cabinets are white and it's all combined.