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13 of the most bizarre lakes in the world

By: Bryan Nelson on Sept. 13, 2010, 11:36 a.m.
Crater Lake was filled up by rain.

Photo: Wollertz/Shutterstock

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Crater Lake

When Central Oregon's Mount Mazama violently erupted 7,700 years ago, it left a massive caldera running nearly 2,000 feet deep right through the heart of the mountain. Despite the complete absence of streams flowing into it, Mazama's crater slowly filled with water over the course of millennia, simply from precipitation.

Today, it is the second deepest lake in North America, and it has some of the bluest, clearest and least polluted waters in the world.