Most day tours show you the South Rim's greatest hits and call it done. The Comprehensive tour keeps going — east along Desert View Drive to the canyon's most dramatic overlooks and the Desert View Watchtower, the stone tower Mary Colter built in 1932 that most day-trippers never reach.
It's the pick for travelers who suspect — correctly — that they'll only do this once, and want the full circuit in a single day: both rims' viewpoints, the Watchtower, and the historic village, with a guide connecting it all.