I think that definition may not allow for a floor but don't really know. I used to live next to a little house that had what we called a cupola at the top of the stairs to the attic. The son in the family used that as a bedroom but it was on that little house long before he was born. It looked rather odd on such a small house.
@buckabucka , yours fits better on a large, fully 2-story home. @Ridgerunner 's idea reminds me of the oldest building on the college campus where I went to school. Some graduate students had offices on the top floor, 4 stories. I wasn't one of them but if my buddy was in his office, I could show up, walk into his tiny closet ... and climb the ladder through the trapdoor in the closet ceiling - flipping a light switch on my way .
I'd emerge in the attic, continue on a walkway above the ceiling joists to another ladder. Through another trapdoor, I arrived on a platform surrounded by ornamental guard rail in the center of the roof.
Since that old building was on the highest hill on campus, I could see for miles! It was a great place to read a book on a warm spring day .
The bird's-eye garden photos must all be on the "real" computer, but DH took this snow view yesterday. He was not exactly in the belvedere, but on the roof next to it clearing off solar panels. I was snowshoeing over to the hoop coop to clear off the front and give the chickens some solar gain. The garden is somewhere under all that snow!
Sorry for all those inundated with snow, but I'm enjoying an unusual winter in Wisconsin right now with nighttime temps above our normal daytime highs. We do have snow. I know I could take photos of a few small piles on the north side of hills that haven't yet melted away yet.
Rather afraid the flowers will start too early and a blast of typical Wisconsin winter will make a mess of the spring. Still, it's nice while I have it to enjoy.