1) The Grand Canyon, located in Arizona, United States, is a massive and awe-inspiring natural formation carved by the Colorado River. It is approximately 446 kilometers (277 miles) long, up to 29 kilometers (18 miles) wide, and reaches a depth of over 1.8 kilometers (1.1 miles).

2) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.

3) The fingerprints of koalas are so similar to humans that they have been mistaken at crime scenes.

4) The word "mountain" contains three vowels: O, U, and A.