Goggle-eyed brontosaurus leftover from the days when this attraction was named Dinosaur Caverns.

Grand Canyon Caverns

Peach Springs, Arizona

Route 66 offers an unhurried retro-pace to its travelers, as anyone stuck behind an RV on its single-lane stretches will agree. But if you really want to get away from it all on the Mother Road, you can spend the night in Grand Canyon Caverns, on a bed 210 feet below the surface, in still air and near-perfect silence, in what may be the world's largest unfinished basement. They'll leave the light on for you, for 1,000 bucks a night.

Entrance passage into the cave.

For those without the cash for an underground sleepover, the cave offers frequent daytime tours, from a quick 15-minute look-see to a more adventurous hours-long spelunking trip -- sometimes with glimpses of the cave's groggy overnighters. Grand Canyon Caverns is a good place if you like the idea of the Grand Canyon but want to skip the crowds, or the heat, even though the Canyon itself is 100 miles away and topographically unrelated.

Ghost tours seek out those who died underground.

The Caverns, like a lot of sights along the Route 66, have evolved over the years to include a little something for everyone. When it opened to the public in 1927 (for 10 cents a tour), the only way down was to be lowered through a hole in the ground by a rope tied to your waist -- a technique affectionately called "Dope on a Rope" and preserved in a wax dummy display outside the current gift shop.

Nowadays an elevator descends into the caverns from the surface, which has become a multi-acre hamlet with hiking trails, a small airstrip, a campground, and photo-ops including several vintage dinosaur statues (Grand Canyon Caverns was once named Dinosaur Caverns, although any connection between them and the cave was purely in the mind of its owner).

A motel offers accommodations for those who don't have the money for the Caverns suite, or if the room has been booked, which we were assured is quite often.

The Mummified Bob Cat: star of Caverns postcards for many decades.

The dryness of the cave is a selling point (and the reason why people can sleep in it without getting wet), although you probably wouldn't notice the lack of water without the tour guide pointing it out. We were told that only three percent of all caves are dry, and with great dryness comes great responsibility: Grand Canyon Caverns was once designated by the federal government as an atomic bomb shelter. The Caverns' 60-year-old allotment of post-apocalyptic crackers and hard candy are still here, enough to feed 2,000 nuclear war survivors, and is a star feature on the tour. In contrast, only a few feet away, is the Caverns' wedding chapel, its white-draped arch and benches overlooking the largest of the cave system's chambers. Flower crowns and bouquets from former marriage parties are strewn along a rock shelf, decomposing at a snail's pace thanks to the cave's ideal climate.

Subterranean bedroom is pitch black when the lights go out.

The absence of water means that other things are absent as well. No majestic stalagmites or towering calcified columns decorate Grand Canyon Caverns. There is also no life, which means that you will not be surprised by creepy-crawlies or slithering creatures. During the tour's obligatory lights-out moment-of-total-darkness you can relax, worry-free; the pitch blackness is calming, like a sensory deprivation tank without all the annoying H2O.

Survival supplies have been sitting here since the Cold War.

This serenity is somewhat lessened by the wall-less bedroom in the middle of the tour. It resembles one that could be found anywhere in the U.S, and sits on a raised wooden platform -- like the set of a sitcom -- beneath the 70-foot-high vaulted cavern ceiling. Board games and dozens of DVDs are provided for the overnight guests, who have to brave onlookers during the early morning tours (This might be your best chance of living out the classic sci-fi trope, the "people zoo").

Also down here is the underground cafe of the Caverns' above-ground restaurant, reservations required.

The cave's ability to preserve what would otherwise decay, along with its lack of a large original opening, has led to what is the highlight of the natural part of the tour -- the mummified remains and mementoes of the creatures who fell down the hole. Since the cave is millions of years old you might expect a pile of bones stacked to the ceiling, but only three animal carcasses receive attention on the tour: 1) a shriveled 170-year-old bobcat frozen in a contorted howl; 2) a mummified coyote, stiff-legged with rigor mortis; and 3) a facsimile taxidermy of a prehistoric Paramylodon harlani or giant ground sloth (Considered an important find, the original sloth was shipped to a museum in the southern part of the state). While clumsy animals falling down a small hole in the ground is an amusing thought, the scratch marks on the craggy limestone walls above the sloth are a grim reminder that it wasn't the easiest way for them to go.

Prehistoric ground sloth fell into the cave and could not leave.

Several fake human skeletons populate the Caverns for a laugh and as a reminder of its grisly past; in its early dope-on-a-rope days the tour included a peek at the real bones of a "caveman" who had fallen down the hole. It wasn't until the 1960s, around the time that the elevator and survival rations arrived, that the caveman was identified as two Hualapai brothers who had died in 1918 while out searching for firewood. Although their remains were removed long ago, the Caverns now offers a ghost tour, and since this place has never been inhabited, or used for any permanent human activity, any post-corporeal interactions probably rely heavily on these two.