Crystal Cavern is a small cavern located in Clay, Alabama, USA, on property once owned by Mr. Larry Shirley, but recently purchased by Alabama Power and entrance made illegal.

This cavern was once open to the public as an attraction in the 1920s, but the operators failed to inform the owners, who lived in Texas, that they had opened a business on the property. There is still the foundation of the old gift shop at the base of the mountain.

The trail is steep and winding, but still has many of the concrete stairs put up in the '20s. Also , several of the internal stairs have been torn out and used for firewood over the years. A curious feature is the large amount of corrugated tin and old Defense Department water canisters inside the cavern. Some say you can hear rushing water or even machinery on the other side of some of the walls.

If you are able to visit this cave, look for the large flow on the right just before the largest chamber. Also there is a ledge over the main passage that is open to it on both ends. (An interesting place to camp.)

In the late 1980s, an effort to clean the cavern was made by a group of local Neo-Pagans, who hauled a generator, shop-style vacuum, and other cleaning equipment into the cave for three days of intense cleaning, mostly of trash left by other visitors and dust covering most of the interior crystal formations. As a result of this effort, renewed crystal formation was reported before the land was made inaccessible by Alabama Power.