The Upper Geyser Basin also includes the biggest and most famous hot spring of Yellowstone: Grand Prismatic Spring!
After our long hike in the Upper Geyser Basin we decided to went to Grand Prismatic Spring by car. Before you got there, the parking lot of the Trail Head »Fairy Falls« is located on the left hand side. A short hike of less than 1 mile and we climbed the hill to look down at the spring from above. I can only recommend this — especially in the afternoon — because from there you have an excellent view of the whole splendour of Grand Prismatic Spring!
Afterwards we had made a short detour to the parking area of the Grand Prismatic Spring, because we wanted to see the red arms of the spring close by!