Cave of the Mounds is Wisconsin's most well-known cave. When my kids were small it was a popular destination for many school class trips and Girl Scout outings.
The Cave was discovered in 1939 near Blue Mound State Park when quarry workers blasted into it. They found stalactites, stalagmites and everything from columns to soda straws, flowstones and draperies. I remember learning in earth science class in primary school that the way to remember which are which is that stalagtites hang tight to the ceiling and stalagmites might grow and someday reach the ceiling. One of those things that stuck in my head!
During October, when you purchase a ticket for admission you can pay an additional $2 and go trick or treating in the cave. You will be given a reusable cloth bag to carry your treats. Inside the cave, you can collect rocks and fossils from the guides along the way. The guides will share information about each of your new treasures.
(pinmapple 43.01731 lat -89.81401 long Cave d3scr)
Photos from my family albums. Footers from @irisworld