The famous balloon analogy to a closed universe is sometimes more of a problem than it is worth. The surface is 2-dimensional, but is meant to represent 3- dimensional space .No matter where you look in the space over your heads, you are always looking within the surface of the 'balloon'. The radius of the balloon represents how 3-dimensional space is curved upon itself by gravity. It's direction is NOT space-like but time-like. The interior of the balloon in this analogy is 'time' not 'space'. The center of the balloon represents 'time zero' at the Big Bang. As you blow up the balloon, its radius increases in time, and the volume of space represented by its stretching surface represents how the 3-dimensional space of our universe is stretching to 'create' more space as the universe expands in time.
The interior of the balloon is not space at all. There is nothing there that can ever be observed by us, because we can only view objects within the space of the surface of the balloon, even the ancient images of very distant galaxies!