Crater Lake is considered one of the most beautiful lakes in the world. The lake is known for its deep blue color, clarity, and beautiful setting in the forests of Oregon’s Cascade Mountains. The deepest lake in the United States and the seventh deepest lake in the world, Crater Lake lies inside a caldera, or volcanic basin, and was created when the 12,000 foot high Mount Mazama collapsed 7,700 years ago following a large eruption. Because the lake is filled almost entirely by snowfall, it is one of the clearest lakes in the world. The present-day water levels are stabilized by a thick layer of porous deposits in the  northeastern wall of the caldera, which acts as the “overflow drain” for Crater Lake. The last known eruption took place at the base of Wizard Island 4,800 years ago, and the volcano has remained fairly quiet, allowing roughly 30 m (100 ft) of sediment to accumulate on the lake bottom. Image: Surrounded by snow, the water of Crater Lake is a deep, gorgeous blue. Photo b...