Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       Astra Plinius - celestial bodies
         Universe
           (Supercluster) Virgo-Hydra-Centaurus Supercluster
             (Supercluster) Virgo Supercluster
               (Cluster) Local Group
                 (Galaxy) Milky Way Galaxy veter.
                   (Spiral arm) Orion Arm
                     (Region) Local Bubble
                       Local Interstellar Cloud
                         (Planetary system) Solar System
                           (Planet-satellite system) Earth System
                             (Planet) Earth veter.
                               "spheres" (Earth)
                                 (Sphere) Hydrosphere (Earth) - layer of water
                                   (Drainage basin) Atlantic Ocean Basin
                                     (Drainage basin) North Sea Basin (Europe)
                                       0.552000N0030000E (Sea) North Sea (Europe)
                                       1.531500N0051500E (Bay) Waddenzee (Netherlands)
                                       2t (Drainage basin) Rhine Basin (Europe)
                                       3.514124N0040418E (Lake) Grevelingen (Netherlands)
                                       4.513557N0035356E (Estuary) Oosterschelde (Netherlands: Zeeland)
                                       5.512228N00.5010E (Estuary) Westerschelde (Netherlands: Zeeland)
                                       6.1 (Estuary) Thames Estuary (Great Britain)
                                       6.2t (Drainage basin) River Thames Basin (Great Britain)
                                       6.3t (Drainage basin) River Medway Basin (Great Britain)
                                       7t (Drainage basin) River Crouch Basin (Great Britain)