The Kitchen floor is raised up from the Hall/Living Room floor, which lead me to believe that the "brick" was actually installed on plywood, on top of the wood floor. I've always wanted a wood floor in my Kitchen. I tore up the metal threshold between the Hall and Kitchen only to find out that there was indeed wood flooring beneath the plywood. And it was level with the Hall floor. Which meant that at least one piece of plywood was coming up so we could investigate. But first I had to remove the linoleum. Which did not want to come up! Scraping, pulling, more scraping... This is the best I could do, after a whole day's work.
Luckily I was able to uncover almost an entire sheet of plywood, which made removing it about 1% easier. It took 2 guys a half hour to lift that thing, which was nailed into the wood floor every 6 inches or so! Unfortunately this story does not have a happy ending.
The floor underneath is indeed wide plank wood flooring that is identical to the Hall and Living Room floors. But it's pretty badly damaged. It's very soft... like it was wet, but it isn't. I could stand on it, but I didn't feel safe enough to have it as a floor. Plus it was very wavy (think wet paper that has dried).
I don't think I can fully express my disappointment. We have 2 options. 1: Put the plywood back and install a new floor on top of it. 2: Tear up all of the plywood and wood flooring, install a new plywood subfloor and new floor on top of that. Well, in case you can't guess, I was outnumbered. So the plywood is going back down and when we install a new floor, it'll be on top of that. That'll make the Kitchen floor about 1/4" higher than the Dining Room floor, but we'll make it work. It's not like anything else in the house is level!