Crystal Lake Cave, near Dubuque, Iowa, is a constantly evolving natural wonder, as streams of water continuously erode and shape the limestone formations. Tour this underground labyrinth and its geology of stalactites, stalagmites and columns. The subterranean complex was originally discovered in 1868 by a miner looking for lead ore.
Walk among the formations along lighted paths as a guide describes various features. When rainwater seeps through the soil above it becomes a weak acid that dissolves and reconstructs the limestone into fascinating shapes that slowly change. Learn about stalactites that hang from the cave’s ceiling, stalagmites that come up from the floor, columns of rock, helictites with erratic spiraling shapes and anthodites with incredible needle-like crystalline patterns.
Younger visitors are able to pan for their own treasures in the Gem Mining Sluice that channels mineral-rich water into a defined area for sifting. Explore some of the more hidden areas of the underground formations with a Wild Cave Tour that takes adventurous visitors farther than the regular visit. The regular tour starts every 15 to 30 minutes and lasts 45 minutes, while the adventurous tour is 1.5 hours and needs to be booked in advance by phone.
Be sure to bring a jacket and wear long pants as the cave often has cooler temperatures even when surface temperatures are beastly hot. The site also recommends wearing closed-toe shoes instead of flip-flops or sandals. You will be navigating a steep set of stairs to get in and out of the cave and passing through some tight areas. Take home a souvenir from the gift shop, which has various items crafted from minerals, including jewelry and gemstones.
Have a family outing at Crystal Lake Cave located 5 miles (8 kilometers) south of Dubuque on Crystal Lake Cave Road. It’s open most days but closed in winter. Children under 4 years old are offered free admission. Ask for discounted rates for other kids through age 11.
