We all know that the Black Hills are a SoDak treasure and home to the most famous caves in South Dakota - and some of the best known in the world: Wind Cave and Jewel Cave, both of which are National Park Service units. But we'll bet you didn't know about this other little crystal cave in the Black Hills. With a history that dates back to over 60 million years ago, dozens of crystal formations that can't be found elsewhere, and tour guides that know what they're talking about, Wonderland Cave in South Dakota, near the small town of Nemo, is the perfect excursion for anyone and everyone.

This is Wonderland Cave.

This cave might be unknown to most, but it's full of incredible formations that most have never laid their eyes on before.

Located in the Black Hills, this cave highlights one of South Dakota's most beautiful attractions.

This particular cave used to be an inland sea, over 60 million years ago.

This history of this cave is interesting and goes back to before the Black Hills were explored.

To hear the full story, you have to take one of the Wonderland Cave tours and learn for yourself.

Each tour is about an hour long, and lets you see first-hand several crystal formations.

In fact, this cave is home to the largest variety of crystal formations, so you'll see interesting features that you won't find anywhere else in the Black Hills.

With informative, friendly tour guides, astonishing views from millions of years ago, and an incredible history, folks of all ages should visit this South Dakota hidden cave at least once.

Have you explored Wonderland Cave in South Dakota? What did you think? Let us know in the comments, and don’t forget to share your Wonderland Cave photos from your South Dakota adventures in the comments, or tag us on Instagram at #onlyinsouthdakota to see your photos featured. While you're in the area, be sure to leave plenty of time to explore all the things to do in the Black Hills of South Dakota.