After Glen Canyon Dam was completed in 1963, the reservoir that gradually backed up behind it, Lake Powell, became famous among recreational boaters and other lovers of water sports. But often overlooked, nowadays, is the stretch of Colorado River that flows below the dam, an isolated 15-mile corridor of calm, crystal-clear waters, surrounded by towering Navajo sandstone cliffs.

The easiest way to visit this remote area is by taking one of the raft trips offered by Colorado River Discovery. Such a half-day excursion starts directly below the dam, where you will board a motorized pontoon boat heading downstream to Lee's Ferry, the gateway to the Grand Canyon.