That’s actually how World Hertitage designation started. After they moved the Nubian monuments to the new location, UNESCO figured out, we should have a list of the most important monuments the World should save wathever it takes, they named them World Heritage Sites. And that is the reason natural things were not allowed to get that designation for a long time, originally it wasn’t its goal.

https://en.wikipedia.org/wiki/International_Campaign_to_Save_the_Monuments_of_Nubia