Crater Lake National Park is a United States national park located in southern Oregon. The centerpiece of the park is Crater Lake which is known for its deep blue color.
Crater Lake was formed from the collapse of Mount Mazama, a volcano that once stood about 11,000 feet tall. A series of destructive eruptions around 5000 BC caused the mountain's peak to collapse into its lava chamber, resulting in a caldera nearly six miles wide. Over time, snowmelt and rain collected in the crater to form the lake, which at 1,949 feet deep, is presently the deepest in the USA, 2nd in North America, and 9th in the world.
The photo on the left is a postcard, I took the photo below.