"A marvel of Depression-era engineering", this "true man-made wonder" straddling the Arizona-Nevada border near Boulder City is "an absolute must-see" rave reviewers who say it's best appreciated via one of the tours led by "personable guides" who make it all the more "exciting" and "educational"; "traffic" and "summer temperatures" may be a deterrent to some, but the majority insists it'd be "ridiculous to miss it" – this is the "one thing the Strip can't replicate."