Marengo Cave, a US National Natural Landmark, is a great cave to introduce your kids to spelunking. Southern Indiana’s limestone terrain has provided the material for many U.S. landmarks – the Lincoln Memorial, the Pentagon, Empire State Building and Grand Central Station in NYC, but it also affects the natural landscape and gives the area some wonderful, small caves and caverns to go spelunking.
As is tradition at my sons’ school, the first grade visits Marengo Cave every year. It’s an ideal first cave experience for young and old. 
They have two tours – the Dripstone Trail that lasts about an hour and the Crystal Place that takes 40 minutes. We did both. I am not claustrophonic, but I’m also not a fan of close spaces or ducking my head to get around. However, because they are relatively quick tours and there are a lot of interesting stops along the way, I didn’t get anxious. The kids were ready to get out of there after about 90 minutes, though.
The kids loved seeing stalagtites and stalagmites, soda straws and unique formations from the thousands of years of mineral-rich water dripping and running through the caverns. We saw an orange cave-dwelling salamander, and the mirror ponds within the cave show exact images of the ceilings above. The guide was wonderful and showed us several shadows, including ones that were in the shapes of George and Martha Washington kissing and a trapeze artist.
Discovered by two children in the late 1800s, the cave has been explored ever since (save a land dispute that left it vacant for a number of years). There are even metal mugs embedded in the cave, left over from early spelunkers who stopped to get a drink at the natural springs within.
You can make an entire day of a trip to Marengo Cave. There are canoe rentals on the Blue River, and you can pan for gems, sifting through dirt to find some treasures. For a longer stay, there are cabins and campgrounds on site.
You could even hop from cave to cave in the area – Squire Boone Caverns, Indiana Caverns and Wyandotte Caves.
