This long wall with a fireplace was made of white cement 'bricks with black mortar between. In other words... 1970's very ugly.
The only thing we left exposed was the slate cap on the hearth which ran the whole width of the room.
We created corbels for the mantle and all surfaces were paneled. These pics were taken before the unit was filled with all their books, pictures, art, crystal, etc. and the painting they had in mind for the center of the wall above the fireplace.