Grand Prismatic Spring

With a name like the Grand Prismatic Spring, a natural wonder has a lot to live up to, and this huge hot spring in Yellowstone Park is more than up to the task with its vivid rainbow ring of colors.

First discovered in the early 1800s amidst the geysers and sulfurous bubblings of Yellowstone National Park, the record-setting natural wonder has been stunning visitors for over a century. The pool is a piercing blue surrounded by rings of color ranging from red to green. The otherworldly effect is caused by varieties of pigmented bacteria and microbes that thrive in the warm, mineral-abundant waters surrounding the hot spring. Changing along with the seasons, the colors fade and grow deeper depending on what type of bacteria is thriving in the weather at the time. The center of the pool, where the water boils up from underground, is so hot that the water is actually sterile. This heat produces a shockingly clear and bold blue color that the spring maintains year-round. 

The Grand Prismatic Spring is one of America's more beautiful sites to look at; just don't touch, as the boiling heat could likely melt skin from bone, mixing blood red into the deep blue.