The idea of 4.36 million cubic meters of concrete alone does not sound the same as a milestone. If the cement, based on the Hoover Dam and its activities, however, that other things. Only a short drive from Las Vegas – and a source of energy for the city of sin gazillion coverage – № 10 is a milestone, you can tour available at night, when crowds of people, well-lit and the masses, as even more of the walls of Black Canyon.