19 natural wonders everyone should see before they disappear


Yellowstone National Park


Yellowstone National Park, America's oldest national park, is experiencing increasing levels of pollution that are affecting its environment.

America is home to some of the world's most stunning natural wonders, but many of these sights are increasingly under threat from climate change and pollution.

While some are slowly experiencing change, others are deteriorating at a more rapid rate.

We've put together a list 0f 19 incredible American natural sights that travelers should see before it's too late, from the majestic Yellowstone National Park to Hawaii's oldest island, Kauai.