The hots springs and geysers of Yellowstone National Park were a wonder. Grand Prismatic Spring was one of the most beautiful of all. To assist us tourists, the National Park Service built walkways allowing close up views. Without these walkways, the people would have had to walk through some very hot water. This would have contaminated the area and would have been dangerous to the people for some of the pools are deep, some of the pools are scalding, some of the pools are highly acidic, most combine at least two of these dangers.