Black Chasm Cavern National Natural Landmark, Volcano

About Black Chasm Cavern National Natural Landmark

Black Chasm Cavern National Natural Landmark in Volcano, California offers guided walking tours through an underground limestone cave system first documented in 1854. Visitors descend into chambers featuring distinctive helictite formations, unusual crystalline structures that twist from the cavern walls in multiple directions. The cave contains a bright blue underground lake and millions of sparkling crystals throughout the passages. The cavern system extends far beyond what early explorers could access, with modern tours penetrating deeper into the underground landscape. Walking tours guide visitors through the accessible sections of the cavern. The site also offers more adventurous Mammoth Spelunking Expedition and Middle Earth Spelunking Expedition experiences for those seeking extended underground exploration. These expeditions provide families and experienced cave enthusiasts the opportunity to venture beyond standard walking routes and witness the geological formations in greater depth.