One of the famous geysers in Yellowstone National Park, due to the presence of biscuit-like sediments around the Sapphire pool in the scenic area, the sediment disappeared in the eruption after the 1959 earthquake, but the name is still in use today. The size of the biscuit basin is about the size of the basin where the large prism is located. The most worth seeing is the Sapphire pool. It is really the bluest and most transparent one I have ever seen in all the pools of Yellowstone. The blue temptation of the test. Although the blue hot springs have been seen a lot, but through the spring water, it is really rare to see the inside of the spring mouth. It is clear how transparent the blue is, and even more wonderful is the spring flow. The place where it passes through has formed a bright yellow water flow that extends all the way to the distance. Firehole (Fire Cave) The rivers and lakes are enchanting, and the riverside bison is grazing.