The Visible Universe probably constitutes a very small (perhaps even infinitesimally small) fraction of the actual physical Universe. The rest will, according to Relativity, always be hidden.
Or it may be that the visible universe is smaller than the actual universe. This paper estimates the minimum possible diameter of the universe to be 24 gigaparsecs, which is four gigaparsecs less than the diameter of the observable universe. It's not likely, but if it were true it would mean we could look a billion lightyears in one direction and see a region of space, or we could look 77 billion lightyears in the opposite direction and see how that same region looked 76 billion years earlier, by seeing light the looped around the long way around the universe.