Boulder City & Hoover Dam

Hoover Dam is the reason this stretch of the Colorado River looks the way it does: a 726-foot arch-gravity dam, completed in 1935 after five years of construction that killed dozens of workers and employed thousands more, holding back Lake Mead, the largest reservoir by volume in the United States. The dam itself physically straddles the Nevada–Arizona state line — a visitor can stand with one foot in each state — and remains fully operational, generating power for three states. A short distance downstream, the Mike O'Callaghan–Pat Tillman Memorial Bridge carries US-93 traffic across the canyon on a modern arch span completed in 2010; its pedestrian walkway gives the single best elevated view of the dam, and it too crosses the state line. Boulder City, a few miles back toward Las Vegas, was built from scratch starting in 1931 to house the dam's construction workforce, and it has never permitted casino gambling — a founding-era restriction that still holds and gives the town a genuinely different character from almost anywhere else in Nevada. Lake Mead itself, managed as a National Recreation Area, extends well beyond the dam and offers its own boating, viewpoints and shoreline access. The area works as a half-day trip from Las Vegas, but it also sits on the direct route into Arizona and the Grand Canyon's western approaches, and treating it only as a Strip day-trip undersells both the engineering and the town.