The craggy halls and twisted tunnels of three caverns—Mercer, Moaning, and California—are open to visitors of all ages.
There is something about a cave that stirs the imagination. Blame primal fear or childhood fairy tales, but you can’t help wondering what awaits you down there in the darkness. Toothless hermits? Enchanted grottos? Scaly, fire-breathing dragons? For those venturing into the caves of Calaveras County, the answer is adventure.Here in the Sierra foothills east of Stockton, the craggy halls and twisted tunnels of three caverns—Mercer, Moaning, and California—are open to visitors of all ages. Whether you choose to explore them on foot, inching along on your stomach, or hanging from a rope, they offer modern-day Alices the chance to discover a rare Wonderland beneath the surface.
A perfect introduction to caves. No climbing or tight squeezes—just 208 steps that take you down, down, down through dripping limestone and face-to-face with stalactites, stalagmites, draperies, and dripstones. As you pass formations like "The Lasagna Factory" and "The Fruit and Vegetable Market," it becomes evident that early cave explorers were very hungry cave explorers. They were also quite intrepid, climbing down on ropes and ladders, their only source of light clenched between their teeth.
Guides are only too eager to demonstrate the pitch blackness these spelunkers faced when their candles blew out. Thankfully the lights flicker back on, revealing the rare aragonite flosferri, the glistening, frost-like deposit that won Walter Mercer the Grand Prize at the 1900 World’s Fair. Small consolation for a man who hoped he’d discovered a gold mine, but beautiful nonetheless.
After Mercer’s intimate grottos, this cave seems enormous. It is: The Statue of Liberty could fit with room to spare. Even the formations are grand: 14-foot stalactites, 25-foot columns, and a giant "chocolate waterfall" that flows like a melted Fudgsicle down the cave wall.
Moaning also offers one of life’s more exciting (or terrifying) experiences: a 165-foot rope rappel. Sure, things seem peachy as you’re harnessed up and sent scuttling down a short rock chimney. But when you catch sight of the 120-foot drop off God Rock (most rappellers emit a repentant "oh my God" here), you think back to that lobby photo of Tom Hanks rappelling calmly, smilingly. And realize why he’s an actor.
From here, the Adventure Trip continues even farther down, through narrow caverns with names like "The Meat Grinder" and "Godzilla’s Nostril." Forget formations—the thrill lies in exploring the cave’s deepest, darkest realms.
If just visiting a cave is adventure enough, thank you very much, walking tours descend via a freestanding spiral staircase. At the bottom lies the source of the cave’s moan: Coke bottle-shaped holes that belch out an echoing "ker-ploomp" when water drips into them.
Of the three caves, California Caverns offers the greatest sense of discovery. Its passageways wind for miles, skirting delicate angel’s wings, breaking out into caverns like the Jungle Room, named for vine-like helictites formed over millions of years. Equally fascinating is the cave’s more recent history as a meeting site for the miners of Cave City. In Signature Hall, the walls are thick with the names of these early visitors, which included Mark Twain and John Muir.
Walking tours explore these rooms along the Trail of Lights. Participants in the Intro Spelunking Tour explore them on their hands, knees, and stomach, cursing that extra piece of cake as they squeeze through passages like "The Worm Squirm." With all the mud and mystery, even claustrophobes can’t help having fun.
But for the truly gung-ho there’s the Downstream Circuit Trip, a five-hour odyssey into the cave’s most beautiful section—the crystalline Middle Earth—and across a dark subterranean lake. You emerge tired, bruised, muddy...and wishing you could do it all over again.
Photos by Peter & Ann Bosted
This article was first published in September 1998. Some facts may have aged gracelessly. Please call ahead to verify information.
Pick up  AAA’s Bay and Mountain Section. map.
- Mercer Caverns , (209) 728-2101. Open Sun.-Thurs. 10-4:30 (9-6 in summer), Fri. and Sat. 10-6 (9-8 in summer). Admission: $7 adults, $3.50 ages 5-11.
- Moaning Cavern , (209) 736-2708. Open weekdays 10-5 (9-6 in summer), weekends 9-5. Admission: $7.75 adults, $4 ages 3-13. Rappel (12 and up): $35. Adventure Trip (12 and up; reserve ahead): $75.
- California Caverns , (209) 736-2708. Open May-Jan., daily 10-5. Admission: $8 adults, $4.25 ages 3-13. Intro Spelunking (8 and up; reserve ahead): $58. Downstream Circuit (12 and up; reserve ahead): $75. Note: Due to flooding, California Caverns is best visited in late summer or fall.