The Palmer Lake Ice Cave is an offbeat little adventure tucked into the foothills above the town of Palmer Lake, Colorado, between Denver and Colorado Springs. Not a typical hollow cavern, it's a maze of passages — at least 500 feet of mostly crawlways — formed in the dark spaces beneath a monstrous jumble of boulders on the hillside. For curious explorers who don't mind getting low and dirty, it's a fun, quirky destination paired with a pretty foothills hike.

Reaching it is half the outing. From the Reservoir Trailhead on the edge of town, a pleasant trail climbs west to a small reservoir; from there, a narrow boulder field and ravine lead a few hundred yards up to the cave entrances. The walk up through the pines and rock is scenic in its own right, and the boulder pile that hides the cave is a fun puzzle to explore.

This is a tight, technical boulder cave, so go prepared and use caution. The passages are mostly crawlways and squeezes through and beneath house-sized rocks — not for the claustrophobic. Bring a helmet and multiple light sources, wear clothes you can scrape around in, and never go alone. Conditions change with the season: in winter, ice can block the entrance entirely, and in spring and early summer, snowmelt and flowing water can make the cave wet, slick, and difficult or unsafe to enter. Late summer and fall are generally the best and driest time to visit.

Note that the Old Carriage Road / Reservoir trailhead parking now requires a small paid permit (around $5–6) from a kiosk, and the lot fills quickly on weekends, so arrive early. Pack water, watch your footing in the boulders, and the Palmer Lake Ice Cave will reward you with a genuinely unique little underground adventure in the Colorado foothills.