Around mid-July, I begin to hate sunshine. This summer, a cure for my seasonal solar disorder hit me like a whiff of guano: I’ll make like a bat and hide out all day in cool, dark caves. (But I’ll draw the line at eating June bugs and mosquitoes.)

Texas is riddled with more than three thousand known caves and sinkholes. These portals to the underworld can be divided into two groups: the ones real bats—and crazed spelunkers—will enter and the ones I will enter. Cavers believe that “where your head will go, the rest of your body will follow.” I do not believe this. As for heavily populated bat caves, if the deadly ammonia levels and the threat of histoplasmosis (a disease contracted from bat guano) aren’t frightening enough, consider this: An average of 268 critters—including bedbugs, skin beetles, and fleas—have been found in random samples of guano about the size of thick cinnamon rolls. What to do? Would I have no choice but to spend the summer in an Omnimax Theater, watching Journey Into Amazing Caves over and over? No way. Thanks to Texas’ show caves—outfitted with walkways, handrails, and electric lights—even claustrophobic chickens can go underground.

I began my descent into Pluto’s domain at the Caverns of Sonora, about fifteen miles southwest of the town of Sonora. On the surface, the place is uninspiring; the visitors center is no more remarkable than a nice barbecue restaurant. Jeremy Robles, who has led tours here for more than a year and still speaks of the site with undiminished awe, escorted me and three other visitors through a pair of utilitarian aluminum doors that help maintain the cave’s constant 70-degree temperature and 95-percent humidity. (The moisture-rich air is as good as any spa treatment; you’ll be positively dewy by the time you leave.)

This cave, which has seven miles of passageways, has garnered gushing praise from speleologists and guidebook writers. I dismissed it as hype—until I took the tour. If the cave were a mental illness, it would be obsessive-compulsive disorder. Except for the narrow walkways, every square centimeter from floor to ceiling is festooned with delicate formations: ice-white Christmas trees, fragile soda straws, mountains of cauliflowerlike cave coral, crystals of dogtooth spar rimming emerald pools of water, and gravity-defying helictites (sort of free-spirited stalactites) that have grown inexplicably to resemble figurines of things like a quarterback passing the ball. And just think, this land of fanciful frosting lay undiscovered until 1955, when four cavers from Dallas finally pushed past the bland first quarter mile of passages—explored by locals for decades—to discover chamber after chamber of mind-bending calcite creations.

A few years later, a group of spelunkers began worming their way into the wilds of Natural Bridge Caverns, west of New Braunfels, beneath the namesake 65-foot limestone span that had drawn visitors since the turn of the century. The cavers’ discoveries resulted in the development of the largest commercial cave in Texas, visited by thousands of school kids every year. I think about half of them were there when I dropped by for the 75-minute excursion. Fortunately, the gnomes went squealing off on separate tours while I and a dozen other grown-ups followed our guide, Dana Snyder, down the switchback path. She rattled off factoids in that quintessential tour voice that’s both lilting and authoritative: “We will descend eighteen floors and return up eighteen floors on our own power” (an elderly couple left the tour at this point). “The temperature is a constant seventy degrees with ninety-nine percent humidity.” “Don’t touch the formations!”

If the Caverns of Sonora are obsessive-compulsive, Natural Bridge suffers from incorrigible grandstanding bordering on egomania. The chambers are colossal—some ceilings are a hundred feet high, and the Hall of the Mountain King is the length of a football field—and filled with monumental formations created over hundreds of thousands of years. With a little imagination, you can make out elaborate thrones, totem poles, enormous draperies, refrigerator-size ice-cream cones, and grinning monsters. No imagination at all is required to see “fried eggs” atop some stalagmites.

Tired of listening to me babble on about these caves, my husband, Richard, decided to come with me to Cave Without a Name, northeast of Boerne. Kevin Schroeder, a young guide with a wry wit and infectious enthusiasm, first showed us the natural entrance, a 45-foot-deep pit that spews cool air. During Prohibition, stills were lowered down this hole and moonshine was brewed in the small entrance cave. After the distillery was abandoned, two teenage boys (and their eight-year-old sister!) climbed down a rope into the pit, dug through a crawlway, and emerged in a chamber the size of a small-town movie theater—which opened into a room the size of a big-city concert hall, complete with an underground river (scuba-diving spelunkers have recently discovered that it flows on for at least two and a half miles farther).

We entered via the mausoleumlike stone entrance that was built when the cave went commercial in 1939, winding our way down the 126 spiraling concrete steps into a world of frozen waterfalls, clear pools of water contained by undulating rimstone dams (tediously formed over thousands of years in a sort of ring-around-the-bathtub method), phallic modern sculptures, dripping grape clusters, and an eighteen-foot-long strip of cave bacon.

Next, our appetites whetted, Richard and I decided to plunge into Kickapoo Cavern, a wild cave for wimps, with no man-made improvements (unless you consider graffiti dating back to the 1880’s an improvement) and no tight crawls. Located in the restricted-access Kickapoo Cavern State Park, between Rocksprings and Brackettville, the cave is open only for infrequent scheduled tours.

A four-inch rain the night before had left our route down RR 674 to the park impassable, and our eighty-mile detour got us to the designated meeting place, the park’s locked gate, thirty minutes late. Luckily, a group of ornithologists who were studying black-capped vireos—but were clueless about the cave—let us in. We drove frantically around the 6,368-acre park without a hint of where the roads led or where the cavern was. As we were leaving, totally disheartened, we spied one last dirt road, marked with fresh tire tracks. After a thrilling four-wheel mudfest, we came upon two Texas Parks and Wildlife vehicles at the bottom of a footpath leading to the top of a hill. Up we went, proud of our tracking abilities, and within minutes park manager Mike Knezek, along with a handful of more-punctual visitors, emerged from the root-wrapped hobbit hole that serves as the cave’s entrance. For some reason (maybe my incessant whining?), Knezek decided to take us back down for a private tour of the enormous cavern. Our flashlight beams played over the twin eighty-foot-tall columns (the largest known formations in Texas), phantasmagoric forests of rust-colored “trees,” boulder-strewn slopes, and ceilings hung with stalactites Godzilla could have used for pole vaulting.

Fittingly, that evening at dusk we ended our adventure by watching hundreds of thousands of Mexican free-tailed bats—my inspirations—as they wheeled out of Stuart Bat Cave, one of the park’s fifteen other caves. For more than an hour the wind-generating vortex of flapping creatures streamed off into the night looking for dinner, backlit by a nearly full moon.

Caverns of Sonora, 915-387-3105, cavernsofsonora.com. From Interstate 10 eight miles west of Sonora, take exit 392 at the cave sign, then go south on RR 1989 for seven miles. Open daily 8 to 6; ninety-minute tour $15 for adults, $12 for children 4 through 11, under 4 free (other tours available).

Natural Bridge Caverns, 210-651-6101, naturalbridgecaverns.com. From I-35 eight miles south of New Braunfels, take exit 175, then head northwest on FM 3009 for eight miles. Open daily 9 to 6; 75-minute tour $12 for adults, $7 for children 4 through 12, under 4 free.

Cave Without a Name, 830-537-4212, cavewithoutaname.com. From U.S. 87 in downtown Boerne, head north on FM 474 for 6.5 miles, then east on Kreutzberg Road for five miles, following the signs. Open daily 9 to 6; one-hour tour $9 for adults, $5 for children 5 through 11, under 5 free.

Kickapoo Cavern State Park, 22 miles north of Brackettville on RR 674; for tour schedule, call 830-563-2342 or log on to tpwd.state.tx.us/news/tpwcal/s_0085.htm. Entrance fee $2. Reservations required; two-hour cave tour $8 for adults, $4 for children 12 and under (liability release required; take sturdy hiking shoes, water, bug repellent, and two flashlights each); bat viewing $5 for adults, $3 for children 12 and under.

For information on Cascade Caverns, Inner Space Cavern, Longhorn Cavern, and Wonder Cave, log on to www.utexas.edu/depts/tnhc/.www/tss/showcaves.htm. For theaters and show times for Journey Into Amazing Caves, log on to amazingcaves.com.

You can’t fling a Visa card from the parking lot of any of the Hill Country caves without hitting a motel or B&B, but around Kickapoo and Sonora the pickings are slimmer. For either cave, try the 1916 Rocksprings Hotel, which Ray and Sharron Croft have been painstakingly restoring for the past year and a half (on the square in Rocksprings, 830-683-4212; $50 to $80 a night). I seldom sing the praises of chain motels, but the Holiday Inn in Uvalde, 62 miles from Kickapoo, was everything it should be: clean, quiet, staffed by friendly people, and shaded by enormous oaks and pecans (920 E. Main Street, 830-278-4511; around $70 a night).