Since Hoover Dam was completed in 1935, much has changed, including the addition of a bridge that rivals the dam as an engineering achievement, yet the older structure remains as impressive as the newer one. Nearly a century after its builders overcame the challenges of the dam’s massive size and remote location, Hoover Dam still delivers power and water as its designers intended. Its Arizona and Nevada spillways direct water around the dam when Lake Mead exceeds capacity, and each of the two spillways can handle the flow of Niagara Falls. Intake towers channel water from Lake Mead through giant pipes called penstocks to the turbines that generate electricity. The site also includes a visitor center and observation deck, Monument Plaza with sculptor Oskar J.W. Hansen’s star chart, zodiac compass, and winged Figures of the Republic, and an original exhibit building whose raised-relief map, completed by master exhibit craftsmen in the 1930s, took more than a year to build.