There are things you should never do in New Mexico.

For instance, get thrown from a horse in the middle of the Gila Wilderness, the way Shana was on the second day of our trip. Even if you land well, you’re liable to twist an ankle.

Or step heavily on the rocks as you’re climbing down from a thousand-year-old cave dwelling. Apparently, the local rattlesnakes don’t like that. They’ll let you know with a shake of a disapproving tail, which is a sound you may hear in your nightmares for a while.

But no one — and I mean, no one — should leave New Mexico without seeing Carlsbad Caverns.

Claustrophobes and chiroptophobes (bat-fearers) may now be excused from this column; a descent into to these famous caves shouldn’t be about overcoming a primal terror.

Instead, the visit should be about awe, a feeling that seems to be less and less a part of modern life.

I’m not sure when my fascination with Carlsbad Caverns began, but it was early in childhood. Perhaps I saw a piece about the caves in an old National Geographic magazine. Or maybe I picked up a brochure about them on a school trip to Luray Caverns, which seemed pretty grand at the time, but which pale in comparison to the sheer scale of the rooms in Carlsbad, which can only be likened to cathedral naves and apses.

Getting there, it must be said, is not easy. Carlsbad is in the extreme southeast corner of New Mexico, not far from the border of Texas. It’s a solid 4 ½ hour drive — at 75 mph, the local speed limit — from Albuquerque across seemingly endless desert flats. In fact, everything in New Mexico seems to be a three or four hour drive from everything else, a phenomenon that it likely to cause a bored and slightly carsick teenager to describe the trip as “worst vacation — ever!”

But the caves themselves are magical. After you finally get there and descend 800 feet to the Big Room, that very same world-weary teenager may get so excited about taking pictures that she runs ahead of you on the trails like a giddy pre-teen.

How did this warren of enormous underground rooms come to exist in the first place?

I’m glad you asked! (And by the way, if a discussion of geological time offends your religious sensibilities, you may also be excused from this column.)

About 250 million years ago, the middle of the United States was host to a vast inland sea, and southeastern New Mexico was prime ocean-front property with a view of a gigantic reef. Reefs, as we know, are made of living things: this particular Permian reef incorporated all sort of creatures, including corals, calciferous algae, and tiny sponges. Over time, the pressure of the overlying water, followed by its evaporation, compressed the reef into limestone.

Back in Earth Sciences class, you may have dribbled hydrochloric acid on a piece of limestone and watched it fizzle. This is essentially what happened in Carlsbad, as acid from the petroleum reserves below the limestone seeped up with the groundwater and etched out giant rooms and pathways.

At this point in the development of the caves, tectonic activity displaced the limestone, lifting it up above the acidic groundwater. The smooth, etched-out hollows drained and dried out. But then another set of processes took over, as mineral-rich rainwater and runoff from above the limestone started seeping down, slowly hardening, over tens of thousands of years, into the spectacular hanging spires we call stalactites; or building up cones on the floor of the cave into stalagmites.

Some of these formations are tiny and intricate; others are monumental. They’ve stirred the imaginations of the millions who have visited the caves since they were discovered at the turn of the last century. Names like “Hall of the Giants,” “Lake of the Clouds,” and “The Queen’s Chamber” may sound like touristic hyperbole, but these spectacular underground chambers live up to the hype.

We had hoped to hike down into the caverns by way of the so-called “Natural Entrance,” a mile and a half trail of steep switchbacks that lets modern visitors retrace the steps of the first explorers, but a certain twisted ankle argued for the elevator, which delivered us to the main cave in three ear-popping minutes.

The trails in the “Big Room” are paved and well lit, and lined with sturdy hand rails. Helpful U.S. Park Rangers are never far away if you have questions.

There’s only one downside to a visit to this natural wonder: the deflating feeling, when you’re delivered, bleary-eyed, to the surface, and realize that your awe, so vivid and huge only a few moments ago, has started slowly slipping away.