A vast flooded former sand mine features an underground lake, boat tours, unique recreational activities, and miles of illuminated caverns beneath the surface.
Open periodically for special events
Check the official website for current operating status and reopening updates
Boat tours typically range from $10–$25 per person
How to Get There
From Festus (3 mi): Take US-61/67 to Bailey Road in Crystal City, head east to Mississippi Avenue, follow the roadway along the industrial area toward the city dump, then take the gravel road leading through the tunnel to the underground complex.
Overview
The Crystal City Underground is one of the most unusual attractions in the Midwest, occupying a vast network of former silica sand mines developed to supply the glass industry during the nineteenth and twentieth centuries. After mining operations ceased, groundwater gradually filled sections of the excavated chambers, creating a crystal-clear underground lake covering roughly 150 acres. Today, visitors are drawn by the opportunity to explore enormous subterranean rooms, experience boat excursions beneath hundreds of feet of bedrock, and witness an industrial landscape transformed into a recreational destination.
The underground environment maintains a comfortable temperature throughout the year and has hosted activities ranging from guided boat rides and kayaking excursions to disc golf, volleyball, athletic events, and educational tours. Massive pillars of untouched rock support sprawling caverns that stretch beneath the surrounding landscape, creating a surreal setting unlike any traditional cave system. Combining industrial history, geology, and adventure, the attraction offers a rare glimpse into a hidden world carved by decades of mining and later reclaimed by nature.
This article uses material from the official tourism pages for the Crystal City Underground and related regional tourism resources, which are released under the Creative Commons Attribution-Share-Alike License 3.0.
