In 1988, Cave of the Mounds was designated a National Natural Landmark by the United States Department of the Interior and the National Park Service. In receiving this honor, Cave of the Mounds was recognized as “a site which possesses exceptional value as an illustration of the nation’s natural heritage and contributes to a better understanding of man’s environment.”

Fun Fact The Cave is over 1 million years old.
Learn more fun facts.

The National Natural Landmark designation is made by the Secretary of the Interior after in-depth scientific study of a potential site. The selection process is rigorous: to be considered for National Natural Landmark status, a site must be one of the best examples of a natural region’s characteristic biotic or geologic features. Cave of the Mounds is a natural limestone cave and is exemplary of this type of solution cave which forms as part of a karst landscape, such as is found in southwestern Wisconsin. What makes Cave of the Mounds special is the quantity and quality of its many speleothems, and the extraordinary colors left behind by minerals naturally present in the rock. Cave of the Mounds is often referred to as the “jewel box” of America’s major caves because of the variety, color and delicacy of its formations.

Our National Natural Landmark plaque is prominently displayed on the Cave Entrance Building. Cave of the Mounds is proud to be a participant in the National Natural Landmark Program. We are committed to the preservation of this unique geologic formation and the land which surrounds it, and we encourage visitors to come experience some of the most beautiful show caving in the midwest!