726 Durham Street, Hellerstown, PA 18055 | (610) 838-8767 | Visit Website

The Caverns are formed in dolomite limestone. Geologists estimate the solution activity of ground water started to percolate through the cracks and joints in the limestone 250,000 years ago. The caverns continue to grow slowly as the Lost River winds its way through many chambers and passageways.
The Gilman Museum, in the Visitor’s Center, features a variety of minerals, fossils, and colorful gems as well as an extensive collection of antique weaponry dating back to the 17th century. The unique gift shop offers rocks, crystals, jewelry, and lapidary equipment. The Gem Mill provides fun and excitement as you uncover your very own gemstones at our water operated sluice. In addition to touring the cave a picnic grove and nature trail are available to guests.
Hours of Operation
Summer (Memorial Day weekend through Labor Day)
7 Days a Week: 9:00AM – 6:00PM
Winter (Remainder of year)
7 Days a Week: 9:00AM – 5:00PM
Closed: New Year’s Day, Thanksgiving Day and Christmas Day
Special Hours: Easter, Christmas Eve and New Year’s Eve