This is one of the most prominent and prettiest thermal pools in the Yellowstone park. The “Morning Glory Pool” was given its name in the 1880 for its resemblance to a morning glory flower. It is a hot spring pool that is colored by the heat loving algae that grow in it. However, this pool was once in danger of losing its colors when the Grand Loop Road used to pass close to it, which increased the likelihood of thoughtless visitors throwing coins into it – thus causing the pool to cool and jeopardize the existence of the color-causing bacteria that thrive within. Today, you’ll have to do a little walking along the Upper Geyser Basin to get to the pool, and it’s well worth the exercise.