Family observing formation speleothem in Cave of the Mounds a place to visit in wisconsin

How Does a Garden Grow Underground? Very Slowly!

Written by Anne Bandow

Springtime, our season of moist breezes, warm sunshine, and budding plants has arrived. As we watch, the surface of the earth goes through swift seasonal changes; underground, where we seldom see, nature works more slowly to create a secret garden of crystalline formations, caverns, and pools. Inside the Cave of the Mounds, Blue Mounds, Wisconsin, a subterranean world awaits all visitors.


In the cave, there are no seasons, no wind nor no weather. Here, the passing years are measured in mere hundredths of inches of crystalline growth. It takes thousands of years for these crystal blossoms to grow to the size of a daffodil.

Photo of our Beauty Rooms with beehive stalagmites and tons of color in our secret garden at this must-see place in Wisconsin​

A tour of the cave reveals hundreds of sparking crystal formations in a gem-like setting. The cave’s environment is remarkably calm and stable. The temperature is a constant 50 degrees Fahrenheit year-round.


As you enter the cave, your eyes become accustomed to the darkness, you begin to make out shapes and colors in the glow of specially placed lights in this secret garden. A chorus of “oohs and ahhs” greets the first view of a mighty ridge of stalagmites rising from the floor of the cave. Above the pathway on the ceiling is the cave’s glistening fissure. This is the source of the countless droplets of water that over millions of years have dissolved enough limestone to form the Cave’s huge main cavern.

Photo of our largest Stalagmite along Onyx Ridge at this must see place

Stalactites, those icicles of stone, reach downward. “Remember”, says the guide, “stalactites hand tight to the ceiling, but stalagmites might grow up there someday.” It takes ages for stalactites and stalagmites to grow. The guide tells us that one cubic inch is formed roughly every 250 years if the conditions are right. And the process continues today. All along the crack in the ceiling, the fissure, you’ll hear the repeated staccato splash of mineral-laden water.

Photo of tour guide in cave which is a great Wisconsin activities

The tour of this underground world usually takes less than an hour. However, with self-paced guided tours, you can take as much time as you need to witness the beauty below the surface. You will pass knowledgeable guides as you walk through the rooms, passageways, and meandering stream beds of Cave of the Mounds. Take time to stop to examine strange shapes and piece the shadows with a well-aimed light.

Before making your way to the familiar world of the surface again, take a last look down the long passage of shimmering crystals.

Once above ground, enjoy the spring weather with a picnic amid the rock gardens and greenery on the Cave grounds. Or walk our trails past the restored woodlands or see a sinkhole up close. You can spend hours in nature while here at Cave of the Mounds.

Photo of a Path through our prairie restoration project with a Barn in the background like a secret garden in the Driftless Area