Admiring the Grand Canyon from the rim is a bit like staring at an aerial photo of the earth—it looks pretty, but the real beauty isn't revealed without further exploration. Although it's hard to recommend a specific duration for a visit to Grand Canyon, any trip into the canyon is enriched by a foray below the rim. If you have the money and time, take a 14-day river trip. If you lack these things but are a strong, experienced backpacker, spend a few days walking on the corridor trails. If you lack the strength or skills for this—and many do—ride a mule to Phantom Ranch. All these trips require some planning ahead of time. And if, by chance, none work for you, set aside a few days for sitting in quiet places on the rim. It still beats driving.