custom_attribute_values:          [:name, :value],
      landmark_nearby_towns_attributes: [:id, :nearby_town_id, :_destroy],
      landmark_countries_attributes:    [:id, :country_id, :_destroy],
      landmark_floras_attributes:       [:id, :flora_id, :_destroy],
      landmark_creatures_attributes:    [:id, :creature_id, :_destroy]