Since 4th grade when i did a country report on Peru, I've wanted to go here. btw, Peru is a great choice for a 4th grader because you get to say Titicaca out loud in front of everyone.
Jumping from a boat into the huge waves to get to hot springs beach was most memorable: "You can't do this in the US," said hubby thinking about safety standards.
Navigating the area around the fountain can be confusing...finding it, as if you were lost and unexpectedly came upon it is most satisfying... Maybe explore the area rather than explicitly planning on seeing it?