There isn't a single proper noun that encompasses all natural wonders. Natural wonders are individual, specific places with unique names.

Here are some examples:

* Grand Canyon: A specific canyon in Arizona

* Niagara Falls: A specific waterfall on the border of Canada and the United States

* Mount Everest: A specific mountain in the Himalayas

* Great Barrier Reef: A specific coral reef system off the coast of Australia

* Aurora Borealis (Northern Lights): A specific celestial phenomenon

* Victoria Falls: A specific waterfall on the Zambezi River

To refer to natural wonders in general, you can use terms like:

* Natural wonders

* Natural phenomena

* Wonders of the natural world

* Geographic wonders

* Geological marvels

Remember that each natural wonder has its own unique name, and that's the proper noun you would use to refer to that specific location or phenomenon.