6. Great Barrier Reef, Australia

As the most well-known place of interest, the Great Barrier Reef is so large that it's visible from the moon -- it occupies 4.79 million square kilometers. It is the home to 400 different corals, innumerable fishes and other marine creatures which feed on corals. The rising ocean temperature has already begun to destroy the sensitive ecosystem here. Maybe, in the near future, the charming Great Barrier Reef will be wiped from people’s view.

Antarctic Peninsula [huanqiu.com]