One of the most famous attractions in the United States, located in the Rocky Mountains, known as the "backbone of America", spanning three states, is the world's largest volcanic basin park. There are various hot springs throughout the park, and the Grand Prismatic Hot Spring is the most famous and the most beautiful hot spring. Under the blazing sunlight in summer, the hot spring water evaporates with reflected blue light, and the various colors of the surrounding sulfur and other minerals form a unique landscape of colorful grand prisms, which makes people linger on the scene.