I was surprised, like Shawn, that the O'Callaghan-Tillman Memorial Bridge had not been entered on Yelp, and I'm glad he did.
What more can one say? I watched the bridge over the years it was being built and I have photos from various stages of construction. It truly is an engineering marvel.
Walking across the bridge gives you a stunning view of Hoover Dam and the beginnings of Lake Mead behind. If you're afraid of heights, the walk may not be for you, but the sidewalk is wide and it's well worth doing.
Every time I've been at the bridge, there have been a lot of people doing this walk. It has become a second tourist destination at Hoover Dam.