Looking for some bucket-list travel ideas? You can't go wrong with these natural wonders—though you might not believe your eyes, even when you're right there.

Another invisible line is the Qinling-Huaihe line, which separates China into two distinct regions: the humid and subtropical south and the dry, temperate north.

From the highest peaks to the deepest chasms, the 7 natural wonders of the world will make you want to lace up your exploring ...