We need pictures of the room - your pictures are so close up that you can't tell what it looks like in the space.

Are you keeping the primary colors?

If you don’t need these open holes, have a contractor fill them with dry wall and paint them. They are definitely odd, especially the one over the sink with a frame around it.

I have a hole like this in my eat in area.

i thought about putting a frame in front of it with a hinge to hide it and keep it usable... right now, my husband puts his wallet and keys and ball cap on the ledge (he doesn't believe me when I say that those don't go there).

I agree though, the best and cleanest way to deal with it is to cover it with drywall.... you could leave a treasure in there or a letter that maybe someone will find one day.

@Jennifer Hogan i plan to change color in blue bathroom

I have a similar situation but I had mine deliberately made this way. it provides a decent amount of storage in a tiny bathroom.

@Diana Bradley yours looks normal! Mine is very awkwardly designed. It doesn’t seem like it has a purpose. no shelving just giant hole.

maybe a shelf or two would break up the space.

But you can frame and both spaces like Diana did...the spaces may be awkward as is but you can modify them and make them useful and attractive.

I would definitely use it as storage by adding shelves and maybe doors! Looks really useful.

I would make shelving for towels.

I love celerygirl suggestions. this takes up no valuable floor room.