What is a world natural heritage?

(1)-Natural features that have aesthetically and scientifically outstanding universal values, and are made up of substances and organic structures;
(2)-Geological, geographical structures and habitats clearly defined/delimited as habitats of threatened/endangered fauna (flora) species, all of which have protectively and scientifically outstanding universal values;  
(3)-Natural places of interest or clearly delimited natural zones that have, aesthetically, protectively and scientifically, outstanding universal values.