While there aren't a tremendous amount of things to do in La Paz, this is one of the sites that is well worth the visit. It is located in the southernmost part of the city and consists of intricate geological formations created by wind and rain. The rock in this area is relatively soft and claylike so it is more susceptible to the elements. The story our guide told us is that Neil Armstrong visited Moon Valley even before he made his first moon landing. Apparently, he made a comment that the area reminded him of the moon. Since then, it was renamed, Moon Valley based on Neil Armstrong's observation. If course, I cannot verify whether this is fact or fiction.
Once at Moon Valley, you walk along a series of ledges that lead to various vista points. The whole thing takes about 40 minutes depending on how slow or fast you go through it. Since we love to take photos, we were on the slow side.