If it would make a nice place to read, I'd stick a chair in there. Otherwise, I'd put built-ins to fill the space.

Not enough information. Can we see the rest of the space, see a diagram (floor plan) that includes dimensions and shows where doors and windows are placed, can you tell us how you will be using this space and and can we know what is behind the niche?

I don’t have dimensions at the moment. Here are a couple more. I’m basically trying to make the fire place the focal
Point. Behind the niche is a spare bedroom

I would definitely turn it into a closet for the guest room.

@palimpsest thanks. I like the closing it in but figuring out where to hang the TV seems like a challenge since the fire place is in that odd area.

Leave just a minor inset in the wall for the TV and use the rest for storage accessed from the spare bedroom. or make this wall perfectly flat - mount the tv and use the niche for storage accessed from the spare bedroom.

I like the niche. It relates to the other arches in the house, and the deep inset most likely helps to reduce glare on the TV. I would wall mount a large Frame TV, and would leave it very uncluttered, without a console. To exploit the ceiling height, I’d mount bird sculptures. In real life, you could do a much better job of placement than this mock-up shows.

That’s a great idea!!!

Your desire was to make the fireplace the focal point but I don't think that is possible simply because it is dwarfed by everything else in the room including the furniture.

That’s why I’m here for ideas to change they :)

That*

Maybe you could do an asymmetrical fireplace like they did in the middle of the 20th century and put the TV off to the side. This places the TV a little high, which a lot of people criticize, but I don't know, I feel like if the screen is big enough it's like watching a movie, and many people I know who have high TVs like them because they can see them from far away while doing other stuff, instead of sitting right in front of it. I don't have a TV, so I don't really have a strong opinion.

If you have room to pull the furniture back a bit, close in the niche to be a flat in line with the fireplace. Hang a TV at a comfortable height, with a console under it that would ideally be the same depth as the hearth tiles in front of the fireplace, to balance that visually. (Unless you have plans to remove those tiles.)

But be sure you can move the furniture enough that the TV won't be uncomfortably close, since it looks like you'd be bringing it forward a significant distance.

If it's not feasible to close in the space, I agree that squaring it off would make the wall more consistent.

Along the lines of ffpalms suggestion: Samsung Frame TV over a built-in bench for reading when the TV is not on - depends if nook has enough depth

Don't remove the niche or the arch. It fits with all the other elements of your architecture. I think you can make the fireplace/niche wall the focal point, but not just the fireplace itself. Keep the Tv on the niche wall, but have a bulit in console or shelving underneath. The materials you use for the niche and fireplace need to blend so it all seems connected. You could use a colored stucco or plaster for the fireplace surround and the back wall of the niche, or choose a tile to go in both places. Bring the top of the fireplace material to the bottom of the arch. If you want a mantle on the fireplace then use the same wood for the top of your builtins.

Those are fantastic ideas! Would the fireplace look out of place if I took the materials up to the ceiling above the fireplace?

Teh arch is throwing off the symetry of the elevation. Square off the arch- if possible, to the height of the hall ceiling.

I recently saw this solution and it's brilliant. Be careful as to the height of the TV as it should line up with something horizontally -- the top of the mantle - would be my suggestion.

Keep the finish of the doors simple to match the walls, add art over the mantle.

BTW anytime a TV is in a space it becomes the focal point always . When I design homes I try to have the TV in one space and FP in the other . Is tahe a functioning FP ? I like the idea of squaring off the arch but I would just do it to match the height of the hallway opening . If it was my space I would close off the niche and just have on wall level across .

It’s funny to me about how many of the comments are about the niche, when I think that you are exactly right, and wanting to make the fireplace the focal point. I think it would look great with different tile, probably something with a pattern. Your mantle would work really well if you get tile that complements it. I can also show you how a friend kind of did her similar set up. However, she does not have the high ceiling that you have.

What is it you don't like in this picture you posted above?