Natura - nature actualia - actual entities Mundus Plinius - physical world Astra Plinius - celestial bodies Universe Virgo-Hydra-Centaurus Supercluster Virgo Supercluster Local Group Milky Way Galaxy veter. Orion Arm Local Bubble Local Interstellar Cloud Solar System Earth System Earth veter. "spheres" (Earth) Hydrosphere (Earth) - layer of water Atlantic Ocean Basin "Canada" (Atlantic coast) Saint Lawrence River Basin (North America) Great Lakes Basin (North America) 1 Lake Ontario (North America) 2.420000N0810000W Lake Erie (Canada, United States) 3.1.445653N0821540W Lake Huron (Canada, United States: Michigan: Tuscola County) 3.2.440030N0864524W Lake Michigan (United States: Michigan: Mason County) 4 Lake Superior (North America)