Marvel Cave is the natural attraction that first drew guests to the area that houses Silver Dollar City, and every guest receives a free tour of it as part of their park admission. A hundred-year lease on it was acquired by Hugo Herschend, the founder of Herschend Family Entertainment (which also runs Dollywood), in 1950.
The free tours last for 60 minutes, and can accommodate 60 people. They pass through a number of caverns, with guests required to traverse hundreds of steps. Mercifully, a cable train drags them back up to the surface.
Since 2006, the park has also offered the Lantern Light Tour, which carries a $10 upcharge and is limited to 20 guests at a time. The cave's electric lights are extinguished, with the old-fashioned, 90-minute tours being lit only by lanterns.