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 system) Atlantic Ocean Basin
                                     (Drainage system) Eurafrican Mediterranean Sea Basin
                                       0 (Sea) Mediterranean Sea
                                       1 (Sea) Alboran Sea (Spain, Morocco, Algeria)
                                       2 (Sea) Balearic Sea (Spain)
                                       3 (Sea) Ligurian Sea (Italy)
                                       4 (Sea) Tyrrhenian Sea (Italy)
                                       5.1 (Sea) Ionian Sea (Italy, Greece)
                                       5.2 (Drainage system) Adriatic Sea Basin (southeastern Europe)
                                       6.1 (Sea) Sea of Crete (Greece)
                                       6.2 (Drainage system) Aegean Sea Basin (Greece, Turkey)
                                       6.3.401251N0262730E (Strait) Dardanelles (Turkey)
                                       6.4 (Drainage system) Sea of Marmara Basin (Turkey)
                                       6.5.410326N0290236E (Strait) Bosporus (Turkey)
                                       6.6 (Drainage system) Black Sea Basin
                                       6.7 (Drainage system) Sea of Azov Basin (Europe)
                                       7 (Drainage system) Nile River Basin (Africa)