After my first spelunking experience a few years ago—in a limestone crevice thirty feet under the city of Austin—I thought I hated caves. The caving instructor had told us, “Just follow the channel,” and promptly scrambled out of sight. So all of us, like lemmings descending into hell, slithered into a passageway that became so tight in places we had to remove our hard hats to squeeze through. My glasses fogged. My right knee kept popping out of joint. At one point the denim rump of the pudgy young woman in front of me got briefly stuck in a stone aperture, like Pooh in the honey tree. The group grew quieter and quieter as we tried to suppress claustrophobic panic. Three torturous hours later I flopped onto the ground in the glorious sunlight and vowed never to crawl into another hole in the earth as long as I lived.

Last February, however, I conquered my subterranean phobia by venturing inside a mountain in northern Mexico. My son’s Boy Scout troop, along with some dads, journeyed to the town of Bustamante to explore the famous Gruta del Palmito. “Gruta” means “grotto” or “cave,” and palmitos are dwarf fan palms; usually associated with East Texas, they thrive, incongruously, on the arid foothills of the Sierra Madre Oriental in the state of Nuevo León.

As we learned, you don’t have to be a caver to enjoy the staggering beauty of la Gruta, which its fans call simply Bustamante. The series of caverns extends into the mountain the length of ten football fields. Massive floor-to-ceiling columns appear to have been dipped in melted caramel. Stalactites hang like sci-fi chandeliers, surrounded by a field of “soda straws,” the delicate precursors of stalactites. “It’s bigger than Natural Bridge Caverns, and it has the formations of Carlsbad,” says one frequent visitor. Just as important, a trip to Bustamante delivers the anything-can-happen experience that I love about Mexico.

The cave is high on a mountainside above the town of Bustamante, accessible by a scenic but heart-stopping drive up a narrow switchback road. For my carful of Tenderfoot Scouts from Austin’s Troop 9, even more exhilarating than the view was a radio program we picked up from Monterrey called La Hora de los Machos. Instead of a celebration of Mexican manhood, the show turned out to be a musical hour sponsored by a restaurant that specializes in a goat sausage called machos. My sixth-grade passengers shrieked along with the ecstatic pitchman as we slowly ascended the road.

We were fortunate to have as our expedition leader Bob Burnett (no relation), a retired cave and white-water expert for the Texas Parks and Wildlife Department whose nearly white beard belies his agility. His advice: “Pace yourselves. Select a foothold and a handhold and move carefully.” He also repeated the caver’s admonition: “Pack it in, pack it out. I mean everything.” The contents of full bladders would also have to be carried out—in empty water bottles. (By the way, don’t ever call a caver a spelunker. “All my friends are cavers,” Burnett said. “‘Spelunker’ is too big a word; it sounds pretentious.”)

Everyone rechecked his gear: water, cotton gloves, lunch, camera, helmet, headlight, and two extra light sources. Somebody said, “Let’s go cheat death,” and we ducked into a discreet opening in the rocks. A local municipal employee named Rogelio Rangel, wearing a sport shirt and loafers, guided us into the cave’s spacious entry room. The descent was slippery but easy, thanks to the addition of concrete steps and electric lights.

The first chamber offers a walk-through version of the children’s activity-book game Find the Hidden Objects. Rogelio pointed out speleothems (cave formations) resembling a Buddha, a baseball glove, a girl in a quinceañera dress, a mummy, a frog, a lion’s paw, a hunchback, and Homer Simpson’s profile. One of the boys christened a double stalagmite formation Jabba the Hutt, the blubbery villain from Star Wars, and everyone seemed satisfied with the free association.

For us, the real caving began at a slippery decline hyperbolically named el Paso de la Muerte (the Pass of Death). The muddy slope has been made significantly less treacherous by the addition of a stout hand rope, which we made good use of. But the Pass of Death was nothing compared with what came next: el Desnivel Grande (the Big Drop).

We found ourselves standing atop a mountainside within a mountain: a boulder-covered slope that dropped seven hundred feet into total darkness. When the water-filled cave drained eons ago, rock from the ceiling tumbled onto the slanted cavern floor. With the faint glow of the lightbulbs behind us, we stumbled through the massive talus boulder field, totally dependent on the beams of light shining from our foreheads. Burnett had a $300 quartz halogen headlamp, but the $5 camping lights most of us had duct-taped onto bike helmets and hard hats worked fine. Nevertheless, the cavern was so immense that neither type of light reached the ceiling, 120 feet overhead.

Bustamante veterans swear that nobody has gotten lost or seriously hurt there in the forty years it’s been open to the public, but trouble could be just around the next boulder. Bustamante is a “wild cave,” as distinguished from a “show cave.” Carlsbad Caverns is a show cave. It has wheelchair access, handrails, and rangers. It also has a snack bar and an elevator, which cavers consider abominations.

Bustamante is at the mercy of the manners and the ethics of its visitors, which over the years have been less than scrupulous. Some Mexican cave clubs have the unfortunate habit of leaving graffiti behind; for them, the cave is a guest book to be signed. Every so often we would find a pink spray-painted signature such as “Los Cobras” or “Los Alacranes” (the Scorpions) on a formation, which in the orthodoxy of cave conservation is akin to scrawling “nice hooters” on the Venus de Milo.

More headway has been made with garbage. Over the years, Mexican and Texan cavers have hauled out some hundred cubic yards of trash, but they haven’t gotten all of it. “Hey, look!” said my twelve-year-old son, Willie, and from a crevice he produced a perfectly preserved Kodak flashcube, circa 1967.

After lunch we hiked to el Salon de Gigantes (the Hall of Giants), where nature in her darkroom had produced mammoth pillars tinted brown by iron or humic acid. Several had toppled over centuries ago and already had new stalagmites forming on them. The effect reminded me of pictures of crumbling Buddhist temples in the Cambodian jungle. But instead of creeping vines, everything was being consumed by drops of calcium carbonate accreting at the rate of a few millimeters a year.

There were small popcornlike formations called cave coral and limestone sheets that had formed from pools long since evaporated, which sounded like timpani when thumped. In this fantasyland it was easy to forget that we were in Mexico until we reached a chamber called el Catedral and saw a votive candle flickering in front of a picture of the Virgin.

We took endless group photographs, swigged water, and began the arduous climb back up the talus slope. After 45 minutes, the darkness and the exertion took their toll, and some of the boys became disoriented, wandering sideways or doubling back. We groped and clambered and searched for that first glimpse of an electric light. For the panting fathers, this was not la Hora de los Machos.

An hour later, staggering into the sunlight, an Austin dentist said to no one in particular, “I’ll be bragging about this for a long time.” One of the Scouts said breathlessly, “There ought to be a caving merit badge.” As we began the short hike back to the cars in our abrasion-resistant, rubber-lug, maximum-traction hiking boots, Burnett informed us that every Easter locals descend into the cave—including women in skirts and church shoes.

That evening, everyone plunged into the warm spring at our campsite just outside Bustamante, called Cañon Ojo de Agua (canyon spring). It’s a standard rural-Mexico public park: outhouses, picnic tables, barbecue grills, and revelers. On this particular Saturday night, a group of young men arrived with a case of Carta Blanca and a boombox and proceeded to pair up and dance together in a stylized cockfight duel. Over tacos of roasted chicken and brisket, we took in the entertainment and looked up at the imposing silhouettes of mountains that were mined for silver three hundred years ago.

As the story goes, la Gruta del Palmito was discovered around 1906 by a local man named Juan Gómez Cazares who was collecting palm fronds for thatched roofs. He investigated the source of the cool air that was seeping from between some rocks and realized that he had happened upon a huge void in the Cretaceous limestone mountain.

If this alluring cave were located north of the Rio Grande, chances are it would have a snack bar, a souvenir shop, a petting zoo, and a cute Jurassic mascot plastered on billboards from El Paso to Orange. And it may be destined for a similar fate: A group of Monterrey and Bustamante businessmen have grand plans to develop the cave and promote it as a major northern Mexico tourist attraction. But for now it remains little known outside of caving clubs.

“What Bustamante has is size,” says Bob Burnett. “For a lot of Texans, it was their first Mexican cave. Later they may get into deep pit caves, and that’s where it gets interesting.” Parts of central and northern Mexico are laced with some of the deepest caves in the world. At 1,100 feet, the famous Golondrinas pit in the state of San Luis Potosí could swallow the Empire State Building up to its observation deck. These pit caves require climbing experience, long ropes, and sometimes, a yen for danger.

In 1969 a 21-year-old caver named Don Broussard joined a nineteen-person expedition exploring the massive cave system near Huautla, Oaxaca. He was on the surface, keeping an eye on the climbing rope that was the only exit for three cavers who had rappelled down a 140-foot entrance shaft. A group of thirteen curious Mazatec Indians arrived, and a few of them became belligerent. Broussard momentarily turned his back on them and never saw which one chopped the climbing rope with a machete.

“I saw the rope flip over my shoulder,” says Broussard, now a computer programmer living in Driftwood. “I turned around and saw all thirteen of them running in different directions.” A woman climber dangling on the rope sixty feet above the bottom of the pit miraculously fell only three feet onto a protruding boulder. Broussard threw down a new rope, and she and the others climbed out safely. “Nobody ever turned their back on a Mazatec again,” he says.

The pleasantly somnolent town of Bustamante, on the other hand, has always welcomed cavers. They’ve become a source of income, along with weekend visitors from Monterrey, pecan harvests, and the Guadalupana mezcal distillery on the edge of town. Cavers buy cold beer at the Deposito la Bautista (literal translation: Baptist Bottle Store). Non-campers stay at the Hotel Ancira (108 Independencia, 011-52-82-46- 03-10), a block off the plaza, where clean, tidy rooms with two beds and a bathroom (hot water included) go for $20; air conditioning and television are $5 more. The kitchen specializes in cabrito, and the dining room is hung with old photos from the cave. The shop next door sells well-made products woven from palmito fronds: hats, tortilla warmers, and thatched-seat chairs.

With an unhurried ambience and friendly old men on bicycles, Bustamante feels farther removed from the frenetic border than it actually is. The town is two hours south of Nuevo Laredo on lightly traveled Highway 1, a side road to Monterrey that is devoid of NAFTA traffic. In fact, except for El Paso, Bustamante is closer to every major Texas city than Big Bend.

First-timers considering a trip to Bustamante should visit the Texas Speleological Association’s Web site (www.texascavers. com/tsa). It contains valuable, if eccentric, information on the cave and has a special section on crossing into Mexico.

A municipal guide is stationed at the cave’s entrance from nine in the morning until four in the afternoon Tuesday through Sunday, waiting for visitors, who pay $1.50 a person. But he won’t go farther than the entry room. If you’re considering going down el Paso de la Muerte and into the Hall of Giants, veteran cavers strongly advise that you go with an experienced caver. Finding one who’s headed to Bustamante is easier than you might think, because the cave is so popular. Every Labor Day, dozens of Texas cavers—from old-timers to beginners—head to Bustamante to pick up trash, scrub off graffiti, and hang out. Try contacting the TSA or the nearest caving club, whose links can be found on the TSA Web site.

Having once vowed never to set foot in another cave, I can’t wait to return to Bustamante. La Gruta del Palmito proved to me that you don’t have to be afraid of the dark.