@MappedSuperclass
public class Place {
   private String name;
   private Country country;
   
   @Column
   public String getName() {
      return name;
   }

   public void setName(String name) {
      this.name = name;
   }

   @ManyToOne
   @JoinColumn(name="country_id")
   public Country getCountry() {
      return country;
   }

   public void setCountry(Country country) {
      this.country = country;
   }
}

@Entity
public class Country {
   private long id;
   private String name;
   private List<Place> places;

   @Any(metaColumn = @Column(name = "place_type"), fetch = FetchType.EAGER)
   @AnyMetaDef(idType = "integer", metaType = "string", metaValues = {
         @MetaValue(value = "C", targetEntity = City.class),
         @MetaValue(value = "R", targetEntity = Region.class) })
   @Cascade({ org.hibernate.annotations.CascadeType.ALL })
//   @JoinColumn(name="unnecessary") // if this, in table country I have field "unnecessary"
//   @OneToMany(mappedBy="country")  // if this, NullPointerException...
   public List<Place> getPlaces() {
      return places;
   }

   public void setPlaces(List<Place> places) {
      this.places = places;
   }

   @Column
   public String getName() {
      return name;
   }

   public void setName(String name) {
      this.name = name;
   }

   @Column
   @Id
   @GeneratedValue(strategy = GenerationType.AUTO)
   public long getId() {
      return id;
   }
   public void setId(long id) {
      this.id = id;
   }
}