The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States, known for its vibrant colors that resemble a rainbow. The spring was first noted by early European explorers and has since become a popular attraction for visitors. Its stunning hues are created by microbial mats of bacteria around the mineral-rich water, with shades ranging from green to red depending on the season. The center of the pool is a deep blue color due to its extreme heat and depth. Overall, the Grand Prismatic Spring is a must-see natural wonder that showcases the beauty of geothermal features in Yellowstone.

If you have the time, hike up and see the view from above, and as with anything in Yellowstone, it can be very crowded.