Grand Prismatic Spring, Yellowstone National Park

Grand Prismatic Spring, Yellowstone National Park (Photo: Krzysztof Wiktor/Shutterstock)

The world's most famous tourist attractions are definitely cool, but that cool also comes with crowds. Forgo the Eiffel Tower and the Blarney Stone for these cool, secret tourist attractions that most travelers haven't heard of.

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Grand Prismatic Spring, Yellowstone National Park, Wyoming

Ditch the tourist crowds at Old Faithful and head to Yellowstone's secret star, the Grand Prismatic Spring. Approximately 370 feet wide and 121 feet deep, Grand Prismatic is the largest hot spring in the park and the third largest in the world. The water may look tempting, but don't dive in—it's around a scalding 160 degrees. The stunning colors are caused by different species of pigmented bacteria, photosynthesis, and refracted light.