Bluespring Caverns lies eight miles east of Williams, near Bedford. The hour-long tour is conducted entirely by boat — visitors descend into the cave and board flat-bottomed electric craft for a slow three-mile round-trip up the Myst'ry River, the longest navigable underground river in North America.
The cave is consistently 52°F (11°C) and pitch dark beyond the boat's lights. The guides point out blind cavefish drifting against the current and the strange formations of the cave walls. It is one of the more memorable underground experiences in the Midwest, particularly in summer when surface temperatures push above 90°F. Tours run daily April through October and weekends through the winter.