The most dangerous phase of Hoover Dam's construction was building the diversion tunnels, two on each side of the Colorado River. Blasting holes 56 feet in diameter, three-quarters of a mile ...

A year shy of its 90th anniversary, experts still marvel at the construction of the Hoover Dam, one of the most visited sites ...

Rising more than 700 feet above the raging waters of the Colorado River, Hoover Dam was called one of the greatest engineering works in history. 5,000 working men and their families came to live ...

6.This is what a typical day of air travel over Europe looks like: 7.This is what a "9 out of 10 difficulty level" puzzle looks like: 8.This is what a Hoover Dam spillway tunnel looks like.

Everything to know about seeing Hoover Dam, including the security checkpoint, whether there's a lot of walking and how to get dam-tour tickets.