Artists Paint Pots, Yellowstone National Park.

Be sure to stop here before leaving the park, you won't be disappointed.This place has all of the four types of hydrothermal features. You can see small geysers, fumaroles (loud steam vents), mud pots, and boiling springs. The bubbling mud was fun to see (and hear).
The colors are truly splendid.  It is almost like a moonscape with beautiful colors. Nature surely is amazing.