I'd have a painting there..that is what I did ..large abstract paintings

whats on the other side of the big wall? can you open it down to kneewall? and open up your solid stair walls with rails?

you should at least find out what it would cost to open things, maybe not as much as you'd think. it would be money well spent, if possible.

otherwise, painting.

LOL>..hang that bear up there! Holy moly, that's the biggest bear I've ever seen! Sorry, couldn't help myself. :-)
Ok, I would do something artsy, but this is probably not everybody's thing. I would go to a salvage business and look for a large leaded glass panel and hang it from the ceiling, on chains, a few inches away from the wall. It could be one big one, or two smaller ones with a few links attaching them together. Some kind of additional lighting would work to highlight it. You could do plain leaded, or stained glass in muted tones. Or depending on your style, any large art piece, with lighting to enhance it.