I've been to Vegas dozens of times however never made it to Hoover Dam so we decided to check it out recently. The drive from Vegas is Hoover Dam is not bad at around 45 minutes. You can pay for parking and go inside for a tour however we chose to forgo that. Since we didn't do this, I'm not sure of the admission cost. We just drove around the outside and took some photos. If you drive further along, there are areas with free parking so definitely don't pay for any parking! If you drive all the way to the end, it dead-ends. There is a small gift shop there as well. This is one of those tourist attractions you should do at least once in your lifetime.