Explore Indiana’s Most-Visited Natural Attraction: A Unique Underground World of Wonders

In terms of tourist attractions, Indiana doesn’t receive quite as much acclaim as neighboring Midwestern states. But far from being a mere thoroughfare to Chicago, the Hoosier State has plenty of worthwhile destinations of its own. Though relatively small, Indiana’s coastline along Lake Michigan is home to the amazing Indiana Dunes National Park, plus the underrated Indiana beach town and prime shopping destination of Michigan City. Indiana’s wonders extend beyond national parks and charming small towns — even beyond the surface level! Southern Indiana’s geologically rich karstlands have a large saturation of amazing cavern systems and caves that offer exceptional descents into the strangely beautiful world beneath our feet. Of Indiana’s many excellent caves, none stand out quite as much as the unique Marengo Cave and its many subterranean wonders. 

Located about two hours south of Indianapolis and just 40 minutes west of Louisville, Marengo Cave is the perfect, family-friendly day trip for travelers interested in a unique but accessible attraction.  Caves of all shapes and sizes tend to feature impressive geological formations. Yet even among this lofty company, Marengo Cave stands out. Visitors who take one of the cave’s many immersive tours will find themselves in a complex and strangely beautiful “forest” of unique rock formations, including some of the most picturesque stalagmites and stalactites in any American cave. Thanks to its immense beauty and geological significance, Marengo Cave is a U.S. National Natural Landmark and Indiana’s most-visited natural attraction.

One great thing about caves is that the underground world operates through a very different set of natural forces than those above the surface. Speleothems, or large underground mineral formations like stalagmites and stalactites, are amazing natural phenomena that often look quite distinct from what we tend to see under the sun. Many of America’s most popular caves are famous for intricate collections of speleothem formations, like the famed Carlsbad Caverns in New Mexico, or the glittering stalactite formations in Nevada’s Lehman Caves. In this context, Marengo Cave has an extremely diverse collection of spectacular mineral deposits. During a Marengo Cave tour, you can see plenty of photo-worthy stalactites and stalagmites, as well as other, more bizarre formations like flowstone, helictites, draperies, and “cave popcorn,” so named because it resembles rocky popcorn affixed to the cave’s walls.

As ancient as it is, Marengo Cave only came to human attention in the 19th century. Legend has it that two young siblings accidentally stumbled across the cave in 1883 while searching for a sinkhole to play in. While this story is disputed, it does serve as a charming complement to the cave’s undeniable beauty. For geologists, Marengo Cave is a notable example of a cave system in the middle stages of its development, offering excellent insight into the complex geological forces that sculpt cave systems across the world. But for visitors, Marengo Cave’s geological prominence means plenty of incredible shots of otherworldly rock formations and a one-of-a-kind underground adventure. And the cave is much more than its artisanal rock formations. As deep and dark as it is, Marengo Cave is also home to a thriving subterranean ecosystem featuring bats, arthropods, salamanders, and fungi.