You could get a piece of glass custom cut to fit and install it as a mirror.

What's behind? You could knock out the indented part to make a real niche, to put a plant or sculpture.

1) When I read "Zen", how about a wonderful painting/print/poster of budda or goddess? Then maybe putting up 'hanging" wall scones. Maybe like these:
http://www.kaboodle.com/reviews/kinnaird-castle-hanging-pendant-wall-sconce
2) A poster or self made print of a wonderful quote since it's the first thing you see when you open the door.
3). Are you open to installing a small water feature? Not sure how costly this would be or if you have to drill into the wall.
I'm glad you are leaving as it until you find the right thing to do with it.
I'm sure AT readers will give you much more suggestions so whatever you decide, I hope you are happy with it. Good Luck

It looks kind of like an arched window shape - you could get someone to paint a tromp l'oeil mural of a window, with a view beyond to maybe an asian style garden or something similarly matching your Asian/Zen style.

Maybe vintage metal wall art, ala Curtis Jere, floating in that space?

Like this:

vintage wall art with copper butterflies

vintage wall art dragonflies

vintage wall art brass butterflies

A really thin modern water drops on glass piece (without the tacky neon lighting) would be cool. Or something more 'rustic' like this maybe http://www.houzz.com/photos/950719/Kenroy-Home-Kenroy-Bamboo-Cascada-Indoor-Outdoor-Wall-Fountain-contemporary-outdoor-fountains- ...I wonder if you could diy one of these bad boys?

Wall mounted ikebana in the center of the recess. Keep it very minimal.

Find an image or print you like, turn it into wallpaper. Cut to fit the niche. Now you have a backdrop to display several skinny, tall objet d'art that strike your fancy. The thing about entries is they are not static. People and things come and go all the time. The niche reflects you for a moment in time. Don't be afraid to try new things and change it up when it starts collecting dust!

perfect place to paint a nice simple mural. dark background with a bonsai tree (maybe a gold trunk), or koi? something like this: http://fineartamerica.com/featured/bonsai-deborah-peacock.html

you could still use the ledge for an ikibana vase w/flowers then.

Looks like a nice place to put a Buddha. Or maybe some bamboo or a branch in a wabi sabi type vase

Mounted Wall fountain for zen-like ambiance? I also kinda like the idea of one long, shallow rectanglular glass "vase" placed on the entire length of the sill, for lining up a row of live bamboo shoots in, at varying heights, for a little bamboo garden.

Or if it's near the front entry, it could be a great landing strip.

Hire a contractor and have it filled in.

Paint the niche with chalkboard paint, and use the ledge to hold chalk. It's actually a very useful thing to have near the front door for reminders.

Love the chalkboard idea, Lisa. Chalkboard/landing strip would be great!

Remove the white ledge. Hang a picture or mirror to cover the entire indent. Alternatively, add some shutters or an Asian screen with a light behind to make it look like a window is there.

Know any artists? That's a perfect place for a trompe l'oeil painting. More realistically, you could apply a subtle, patinaed metal leaf to the inside of the niche to set off a scroll, a carved relief plaque, a textile, etc. I did that effect in a deeper niche using metal leaf paint I got at a craft store (Modern Masters water based metal paint). I used a range of aged golds to white gold, opaque and semi-opaque. I built up a layer with a stiff brush, wiped much of it off. Built up a layer of a different color, wiped it off, etc. I ended up with the look of old metal leaf without the squares, and I placed an aged bronze sculpture on the shelf.

Another look would be one beautiful wall pocket holding a plant or cut branch ((AT featured an Etsy seller who makes gorgeous wall pockets that look like half an egg with a leather hanging strap). You could also put up a small shelf inside the niche and display a modest Ikebana arrangement there, changing the style with the seasons...in the manner of tea ceremony.

If it really is right when people walk in, I would hesitate to put anything on that ledge that could get easily knocked off. I tend to agree with ZZZIPER - remove the ledge and put something over the whole indented part. Mirror, art (would have to be really big) or even a piece of furniture. Alternatively, I would remove that ledge and replace it with a deeper ledge, so you can make a little vignette there without fear of things falling off. In that vignette: a framed photograph of an asian temple? a small fountain? a plant (depending on how much light that space gets)?

I like Duane Hill's idea best.

I have a similar niche near my entry that I finally filled with a custom made bulletin board. Find some fun fabric then go to a craft store (I went to Michaels) to get some foamcore/cork/batting to make the bulletin board. I then applied it to the wall with velcro so I can remove it and re-cover it down the road.

You've gotten some great ideas here! My favorite is the vintage metal wall art, suggested by tequilared. Putting art work make the most sense to me, and having something 3D makes sense with the shallow indent. Otherwise, I would hang a row of those tall, skinny test tube looking vases and put a row of bamboo. I love fresh, living plants when I first enter a home.

The safest bet is probably just to remove it entirely, or at least remove the shelf and cover with art or a mirror

This seems more illogical than charming (I have a very similarly built in shallow bookcase and I just covered it eventually. Nothing would stay put, and it always just looked somewhat unnatural)

I think it's an interesting little area - don't cover it in! Lots of great ideas - isn't AT great for ideas?!

I agree with those who say to paint or paper it with some kind of bonsai-ish or other Zen-ish silhouette or something simple like that. It might be hard to find a small amount of wallpaper even if you find the perfect design, but you can put fabric on the wall like wallpaper (lots of DIYs online, including here on AT) and you may be able to find the perfect fabric.

Also, if the niche is deep enough (or if you make it deeper) you could consider hanging something there, even if it's in front of the background pattern.

Hope you share some 'after' pics! :)

I had something similar in a rental unit once and I set it up as an alter. It was a perfect look for the niche and helped me express my style in a way that was meaningful to both myself and my guests. Considering your decor style, it may work perfectly.

Good luck!

It depends if you are wanting to do something yourself or hire someone. There are some amazing glass mosaic artists out there. I've seen some take virtually any photograph and duplicate it in glass with amazing detail.

On the other hand, if you are crafty and want to give it a shot yourself consider using items like river rock or beach glass (you can cheat and get 12x12 netted pieces from the flooring stores!) and incorporate wall mount planters for bamboo or air plants (which require no soil). This should help make a nice zen/tranquil focal point that is alive.

Alternatively you could have a piece of glass cut to fit that space and either use an etching kit to etch a design (bamboo? Bonsai? Orchids?) or use a kit to create a backlit stained glass piece there.

There are lots of options!

I like the Asian/Zen look, too.

I'd either hang a small Chinese scroll (with a decorative pin holding the hanging cord near the top of the niche, justifying the arch), possibly after painting the niche a contrasting color or even lining it with something like grasscloth (remnant??)

Or, I'd install a little shelf for a vase of ikebana (and although it's kind of counter to the true spirit of ikebana, I'd consider silk cherry blossoms or something like that -- pragmatically, they don't need to be refreshed every other day!) A wall pocket would also work.

Both concepts are pretty Asian in flavor.

Another idea - make it a faux window and hang a planter box on that little ledge with some nice ivy? random thought. lol

I'm thinking a super narrow box/vase (maybe a diy hammered copper box or glass with pebbles) that could be secured for safety's sake. In the box I'm thinking bamboo cut at lengths that follow the arc and spaced enough. This would give the illusion of depth. If you wanted to do even more, try adding a strip of light behind or to the sides to create interesting shadows and illuminate the area artfully.

It is too interesting an architectural detail to knock out and fill back in. If it isn't reasonable to knock it out to the other side, I would install a mosaic either myself or hire a ceramic artist.

AT IS WONDERFUL! Such great ideas...now I just have to choose! Thanks SO MUCH to everyone!!! Don't hesitate to keep on commenting!!!!

If you really want to get dirty, I think you could install some sort of fountain in there. But be careful - it's a fine line between tacky and very cool.

I think it would be cool to wall paper the nook with a cool print and then put some framed artwork there!

I have 5 of these in my house and I love them. For the one at the top of my staircase I got a big wooden Virgin Mary on a trip to Mexico. I've got a kind of shrine going there which I love because I see it so often; that's what I imagine for you--except with your Asian-Zen vibe. It could set the spiritual tone as you and your guests enter your home. In the living room I have one with 2 prints by an artist I like and glass orbs and globes along the sill on the bottom. In the bathroom I have 2 of them with cacti, succulents, and big painted Italian tile I found left behind by my home's previous owners. I haven't committed to what to do with the one in the kitchen yet. My home's previous owner hung paintings in them and placed (fake) ivy in long low pots along the bottom and placed ceramic pitchers on them as well. (I went that route for a while but then moved the pitchers.) Don't fill it in! It can rotate so many different things!

It looks like it was probably intended for a cross or something to go there. Looks like a little altar. I would definitely go with the chalkboard paint and put chalk on the ledge and either install some cool wall hooks by it or put a hall tree by it, and maybe a little bench underneath it for putting shoes under or for kids to stand on to write on the chalk board?

had a similar issue i came up with this in an afternoon
http://onesix3twocustom.blogspot.com/2012/08/blog-post.html.

What about a vintage gong? Something like this: http://www.amazon.com/Woodstock-Chimes-EZTG-Table-Gong/dp/B00112X5AS

Paint the interior of the niche a bold color, to make it seem purposeful. Very zen!

There was a recent AT posts featuring some air plants---these would look really nice:
http://www.apartmenttherapy.com/one-of-a-kind-air-plant-vesselsetsy-roundup-175035

Back - Bamboo, Bonsai, Cherry Blossom, Japanese Maple, Orchid,
Ledge - Stacked Pebbles or Miniature Sized: architecture, bridge, figurines, vases

The alternative:

Back - Decorative Japanese Plate, Gong Wind Chime
Ledge - Miniature Sized Oriental Plants, as above

I also like the idea of having a custom-made mirror mounted in that niche, or hang a painting. You could have a mural artist come in, and custom design something in your style. If you realling dislike this niche, have it filled in or hang something larger than the dimensions.

What about making some paper crane strands and hanging them in there?

I love the "landing strip" idea, especially since it's at your entrance. In my case, it'd be a hook for my keys, a hook for the dog's leash, a place to stow my sun hat, a place to hang my purse...

But it is also a great display area for a 3D object of some kind.

I'd hang a beautiful Nepalese Thanka. Very striking!

a mirror would be the typical option....but we arent typical people. But the nice thing about the mirror is that it provides light and shine. I would first paint the alcove a black or dark brown, then i would silver or gold leaf right over the paint. If the lines dont match up perfectly between the square leafs thats fine because the black underneath will make it look like an old chinese screen. Then polish it to almost a mirror like finish. Then i would find an image of a cherry blossom branch with a bird or something and freehand paint over the leaf. it provides interest, shine, and art without remodeling or hiding it, and if you hate it someday you can paint over it.

How about metallic-leafing the niche (gold, silver, whatever suits you) before putting a simple vase of branches on the shelf?

If that part of the wall of the niche could be opened; stained glass...

Vertical succulent garden

If you dont like it, and its nothing charming or useful or original to the house, why not just close it up. 15 minute job to sheetrock it. I have one of these in the house I moved into, I found it useless so I put a chalkboard over it... also useless, but I like the look of it better than the shelf. I dont like everyone's suggestion to install a mirror in it - that sounds tacky and '80s' to me. If you want to roll with it... paint the inside a different color - either contrast or tonal to your wall color, maybe just hang a framed photo in there and some small (if you can even fit anything) vases with some long reeds or grasses or that sort of thing

You said it's the first thing people see -- but from how far away do they see it?
The size of the floorspace matters here. If it is elbow-room with the door, you wouldn't want a sculpture, for example. Would you spill the beans?

Since there's electric just near the space, I'd be tempted to take the stained-glass idea mentioned above and mount it to mimic a real window, with a low-temperature back-lighting.

Which makes me think of something seen in a Danish museum*... A rescued historic room was set up with its windows "looking out" on an artist's rendition of the city that would have been outside it at the time it was new. All was done in silhouttes, and the area between the windows and the artist's mural was gently lit. Quite lovely, and the idea might be made to work. (Aalborg Historiske Museet, if you're curoius.)

What about hanging a kokedama plant ball so that it is framed by that area?

Traditional Japanese way of decorating that kind of space is hanging a scroll of landscape and putting an object(s) together.

Such as:
Landscape of sky and bird figurine.
Landscape of river and fish figurine. This is good for summer.:-)

Just like you all do, we enjoy each season with decoration.
Have fun! :D and just change the ledge. It's not "zen."

I'd cover it up completely. Those shallow little ledge/niche things are a decorating nightmare (nothing fits and it always looks awkward).

Decorating should be easy and flow .. if something like this is stumping you then it should be eliminated.

I agree with the others suggesting an indoor wall hanging fountain: http://www.windandweather.com/classic-wall-fountain_p787.html. Please post your after photo once you redo it. Good luck!