Originally was supposed to be a broom closet

I'd paint the inside white or silver and hang a broom in it

https://www.chairish.com/product/8055542/african-baule-broom-with-a-male-figure-31-h

Could be a bit of fun if you got a real handmade broom , I agree not the finish there now.

If you have a door for it just put the door on and ignore it, or you can drywall over it. It doesn't look very useful to me. The dining room is an unusual choice for the location of a broom closet.

What a unique feature. I love the idea of playing it up as it was apparently intended. Even the dog bowl could stay.

It would look great with shelves.

The wood has to stay it is pieces of an old door from my great great grandparent's home but i love the unique broom idea!

I'd do shelves. Built-in china cabinets used to be common in houses. It's a place to display china and silver. If you don't have any, silver plate is cheap at auctions and vintage stores.

how about putting in some shelves and paintin the same as the trim?

this is from pottery barn, but it gives you a visual

you can do 2, or 3 or however many you want.

space them out. display pottery or something that goes w/that room style.

is that a dog bowl on the floor? maybe display some framed pics of your pet?

Shelves with collection of vintage ceramic pie pans.

Glazed Terra Cotta Pottery Deep-Dish Pie Plate, Blackbird Motif · More Info

I would put a door on it and make it a pantry or storage for plates and glasses. Mostly because it has the same trim as your other door and it’s kind of fun to have a ”mystery door”.

I wonder if you could get a single bifold door panel that matches the other door and is the right height, then install hinges to make it a swing door or cabinet door.

Do you have a vase from your grandmother, or that era? Then go to the stores like Hobby Lobby, Michaiel's, etc and get some tall dried flowers or plants. I had some twisted dried "sticks" a long time ago in my bedroom in a woven vase that I loved.

ETA: They were a kind of grass plume.

Man you guys are awesome, what great ideas!

Shelves to display objects. One object per shelf that takes up most of the shelf. Silver pitcher, framed photo, serving bowl. That kind of thing.