Behind Crystal Cave’s spider-web-like gate lies Sequoia National Park’s secret underground world, a landscape of glittering mineralogical features. It’s one of more than 200 marble caverns found within Sequoia & Kings Canyon National Parks. The parks contain half of California’s caves that are more than 1 mile/1.6 kilometres long, as well as the state’s longest cave. Most of the caves have limited access for research purposes, or require experience and equipment. But not Crystal Cave, which is open for guided walking tours mid-May through November. (Note: no strollers or wheelchairs.)
Crystal Cave, first discovered in 1918, is hardly a secret: thousands of people explore it every year, and the underground route has paved paths and solar-powered electric lights. The standard 50-minute tour is a great choice for the mildly curious and families with young children, but it doesn’t rate high on the adventure scale. For a more exciting experience, sign up for the summer evening “Explorer’s Lantern Tour,” when the lights are turned off and visitors carry candle lanterns. The biggest thrill is found on the Saturday-only “Adventure Tour,” a 4- to 6-hour belly-crawling trek. Headlamps, kneepads, and elbow pads are provided, and participants should be prepared to get dirty as they stoop-walk, crawl, and climb through off-trail passageways. Only in caves like this can you experience the eeriness of total “I can’t see my hand in front of my face” darkness.
The cave is located at the end of a winding 7-mile/11-km road off the Generals Highway near Giant Forest. For all tours, advance planning is required. Buy tickets at Lodgepole or Foothills visitor centers (tickets are not sold at the cave). Driving to the cave from either visitor center takes about an hour, plus you need additional time to hike the steep half-mile/0.8-km to the cave entrance. And don’t forget a jacket: It’s about 50 degrees inside Crystal Cave no matter what the temperature is outside.