Hoover Dam was named one of the Top 10 Construction Achievements of the 20th century. Hoover Dam is a great accomplishment for residents in Nevada, it controls floods and stores water for irrigation and other activities that affects a lot for people there.
Hoover Dam is located in Black Canyon, just few minutes outside of Las Vegas, so there are many vistors who come to Vegas would stop by Hoover Dam.
During the tour in Hoover Dam, you could understand the history of it (they played a short video at the beginning of the tour) and how did it build. You can go to the inside of Hoover Dam to see how it works. They also provide free expositors.
Besides, there is an observation desk where you can see the panoramic views of Colorado River and Lake Mead.