This is something one would come to visit once, and once is enough.
I first came here 15 years ago with parents and don't remember much about it... this time I got to learn more about the history and the architecture of the dam. it's just one massive block of concrete that was ingeniously built for the benefit of water and electricity resources. It was built in 1930s and under budget and ahead of schedule, something modern day engineering does not see much..
still, very impressive sight to see, make sure you get there early in the morning or they run out of tour tickets until the afternoon... ~~ about a 2 hour drive away from LV strip given no traffic.