This is a room that has no floor, no walls, no windows, and also no door. what is it?
... have no clue ...
A mushroom?
The answer to this riddle is "a mushroom." It may seem like a paradox, but when you think of a mushroom, it doesn't have a floor, walls, windows, or a door. It is an object that grows on the ground, resembles a dome-like shape, and doesn't have any clear openings or barriers.
To find the answer to riddles like this in general, it often requires a combination of critical thinking, imagination, and lateral thinking. In this case, understanding the unique characteristics of a mushroom and how they relate to the description provided is key to solving the riddle. By breaking down the riddle and analyzing the possibilities, you can arrive at the correct answer.