SOUTH DAKOTA
— While South Dakota’s wide-open plains and iconic landmarks often capture the spotlight, a network of fascinating underground attractions is quietly stealing the show. From intricate cave systems to a gold mine turned world-class research lab, the state’s subterranean marvels offer a glimpse into geological history, scientific discovery, and Indigenous heritage.
Jewel Cave: A Labyrinth of Natural Art
Located near Custer,
Jewel Cave National Monument
ranks as the third-longest cave in the world, with over 220 miles of mapped passages. Named for the glittering calcite crystals that line its walls, the cave is a wonder of
stalactites, flowstone, and delicate formations
sculpted by nature over millions of years.
Visitors can choose from guided walking tours or strenuous spelunking adventures, with rangers offering insights into how the cave was formed and continues to evolve. Despite its vast known length, researchers believe much of Jewel Cave remains undiscovered, adding a layer of mystery to every visit.
Wind Cave: Sacred Depths and Boxwork Beauty
Just 30 miles away lies another underground treasure —
Wind Cave National Park
, known not only for its unique boxwork formations but also for its spiritual importance to the
Lakota people
. Recognized as one of the
first national parks
in the world to protect a cave, Wind Cave offers a quiet, otherworldly beauty beneath the Black Hills.
Wind Cave’s signature boxwork — a honeycomb-like calcite pattern — is found in few places on Earth. Above ground, visitors can also explore
rolling prairie, bison herds, and hiking trails
, making it a dual experience of both surface and subterranean beauty.
Homestake Mine: From Gold to Galaxies
In the town of Lead, South Dakota’s underground narrative takes a scientific turn. The
Homestake Gold Mine
, once the deepest in North America, is now home to the
Sanford Underground Research Facility (SURF)
. Scientists here study
dark matter, neutrinos
, and the mysteries of the universe — all from more than
4,850 feet below the surface
.
Once a cornerstone of the local economy, the mine has been reborn as a hub of international research and innovation. Public tours are available at the nearby Sanford Lab Homestake Visitor Center, where guests can learn about both the site’s gold rush past and its high-tech future.
Hot Springs and the Mammoth Site
Farther south in
Hot Springs
, yet another layer of South Dakota’s underground story is on display at
The Mammoth Site
, where ongoing excavations reveal Ice Age fossils in a former sinkhole. It’s one of the world’s largest sites for Columbian mammoth remains and offers an active dig site experience for visitors of all ages.
A Journey Below That’s Worth the Trip
Whether you’re drawn by natural wonder, scientific curiosity, or cultural significance,
South Dakota’s underground attractions
provide unforgettable adventures beneath the landscape. As summer travelers seek new discoveries, these unique destinations remind us that sometimes the greatest wonders lie
just beneath our feet
.
What’s your favorite underground discovery in South Dakota? Tell us in the comments — and let us know if you’ve explored any of these hidden treasures firsthand!
