Nothing in our experience prepares us for this. Our primal fear of descending into darkness reins us back, yet we strain at the rein. Something calls to us from below, and we answer with cautious steps. We’ve heard that wonders await us down here, and as our eyes adjust to the dim light, we begin to see them. Chambers hung with curtains of swirling stone open before us. From the chamber floor, jets of stone spike upward; stone fangs dangle threateningly from the ceiling. Stone is massed in fluted columns like organ pipes and stretched fine as frozen wings. We’ve entered the magical realm of Mercer Caverns.

If you’re searching for a cool place to spend a hot day within striking distance of East County, an 87-mile drive east of downtown Brentwood – five miles past Angels Camp just outside the town of Murphys – brings you the surreal sculpting of the “Showplace of the Sierra.” In fact, if 55 F strikes you as an overly aggressive solution to the heat, you might want to bring a jacket.

Natural forces have been shaping Mercer’s subterranean realm for 3 million years. In prehistoric times, the native Yokut tribe used the caverns as a mortuary, rolling their dead down the fissure’s opening. In 1885, purely by chance, the caverns betrayed their existence to Western civilization. While lounging under bay trees near a limestone rock, a gold prospector named Walter J. Mercer noticed that a nearby patch of grass was quivering as if stirred by a breeze from below. He found a fist-sized hole in the ground, expanded it, tied a rope to a tree and then around his waist and lowered himself into what would become one of the West’s most breathtaking natural wonders.

It’s not difficult to understand why Mercer Caverns takes the “Showplace” trophy. A descent into this darkness is truly enlightening. The journey takes you down 161 feet – the equivalent of a 16-story building – past limestone formations with names like Angel Wings, Beehive and Organ Loft. The Angel Wings are a pair of rippled, banded, translucent curtains more than nine feet long, three feet wide and 40,000 years old. The Beehive is a massive 200,000-year-old stalagmite that takes between 500 and 700 years to grow one cubic inch; and in the Organ Loft are suspended the Organ Pipes, an array of narrow columns soaring to the cavern ceiling.

The earliest tourists to the caverns were required to negotiate some harrowing passages – by candlelight – and get grimy in the process. As a magazine article dated 1893 put it, “Visitors should wear clothes which they never expect to wear to a wedding afterward.” Today, 88 lights reveal the cavern’s marvels. Sturdy wooden and concrete stairs, platforms and walkways – plus an abundance of railings – make the odyssey below safe and easy.

One of the most impressive sights in the caverns – and the one that captured the 1900 Paris World’s Fair’s Grand Prize for subterranean formations – is found in the Flower Garden. Here grows a rare structure called Aragonite flos ferri, the branching crystals of which form delicate bushlike blossoms such as you might see clinging to the floor and walls of an undersea grotto. When standing in the Flower Garden, it’s hard to tell if you’re under water, under ground or under the spell of a waking dream.

The tour lasts about 45 minutes. As long as you’re in the area, a jaunt to nearby Ironstone Vineyards gives you the opportunity to view another treasure conjured by the alchemy of earth: the largest specimen of crystalline gold on the planet. The 44-pound phenomenon is no boring lump of rock, but a glistening, finely textured sheet of leaf gold, an object worthy of the most epic quest any civilization’s mythology could imagine.

After you’ve viewed the gold and enjoyed a few sips in the vineyard’s tasting room, don’t be in too great a hurry to get out of town. Murphys lies directly in the path of your trip home. The burg is well known for its quaint shops and good restaurants, and is the perfect venue for a rejuvenating stroll following your adventures in caves and gold and wine.

To inquire about tours of Mercer Caverns, call 209-728-2101 or visit www.mercercaverns.com.