This giant natural cave is right below one of America's favorite theme parks (and yes, you’re allowed to explore it).

Cave Rock is located off Highway 50 ... an out-and-back hike that takes visitors about an hour to complete and features waterfalls, granite peaks and even swimming opportunities.

More than 20 years later, local cave explorer ... underground waterfall. Carrying out Lambert's vision, visitors can take an elevator down to the falls and learn about the various rock formations ...

But little did I know that just below me was an entire natural cave waiting to explore.  Marvel Cave at Silver Dollar City ...