I LOVE the mosaic ideia! I would do in a open area easy or in a kitchen or bathroom area too.

Hi, I'm from Brazil and here we basically use to types: if it's narrow there are some like looks like the floor or "stones" like marble. And now I'm looking to the floor of my apartment and thinking that it needs to change too, help me! Idk why marble and stones are cheaper here so it's the most common. But maybe you can do with small tiles like smaller than subway titles?! You can do a art or just plain. If nothing else works I would fill the hole with something like any filler and throw a carpet over. Something that would go from room to room to give some identity. Good luck and show us the result!