The heavens and all that is in them.
Early man was tremendously intelligent. Adam was the perfect man. The feats of memory, reasoning, and logic that show up in some individuals today are endlessly copied corruptions of Adam's intelligence. By biblical chronology, it took only seven generations to go from what was effectively the stone age to the iron age. When you consider that technology is cumulative and self-reinforcing--it's a lot easier to design an injection molder when you don't have to design a socket-head cap screw and alan wrenches first--that technological leap is absolutely astounding.
No imagine a world without sin, and thus most obviously, without the Flood. Without the Flood, human history would be 1600 years more advanced. Without sin, and the retarding effects of war, disease, and Malthus, or the splitting of the peoples at Babel, by this date the first moon landings would be ancient history. Humans would live and move through the solar system, and probably have journeyed to the nearer stars. God created an entire universe for humans, and the earth was just our cradle. It is sin that keeps us here, and makes us wonder about the purpose of the vast creation.