Grand Prismatic Spring

If you have brought only one roll of Kodachrome to Yellowstone, this is your stop. The largest hot spring in the park, the Grand Prismatic Spring is indeed all three: grand, prismatic, and a spring.

The boardwalk talkes you right up to it, wending past the Excelsior Geyser Crater. But for another view, I suggest climbing up the hill to the east of the parking lot. The climb will give you a panoramic view of the Grans Prismatic Spring and the whole Midway Geyser Basin.

And here's a bonus photo from the hill, showing Grand Prismatic Spring with Excelsior Geyser Crater: