There's no road like the Mother Road. The 75-mile stretch from Seligman, Arizona, west to Kingman looks much like it did half a century ago. It's a vast expanse of high desert with few services, so fuel up in Seligman and tour the museum in the Route 66 Gift Shop. Twenty-five miles west, check out the Grand Canyon Caverns, the country's largest dry caverns, then continue to Kingman and I-40, or drive 60 miles north for the ten-mile trail to the turquoise waterfalls of Havasu Canyon.