Minnesota is home to only a few well-known caves. Mystery Cave is probably the most famous, with the nearby Niagara Cave coming in close behind. The Wabasha Street Caves, though manmade, are another common stop for those who love underground adventure. These caves are popular, but Minnesota has many more unnamed caves that you’ve likely never heard of. One of the most interesting is an aboveground cave near Stillwater that will give you a surreal experience. Take a look:

Most people haven’t heard about the St. Croix Boom Site near Stillwater, Minnesota. This wayside stop is a fascinating look at Minnesota history.

McGhiever/Wikimedia Commons

This attraction is the site of a log boom that lasted from 1856 to 1914. Logging companies sent timber down the river, where they were caught in the boom.

RTCA NPS/Flickr

Though the St. Croix River no longer has logging activity, it is still a busy river. Many use it for boating, fishing, and even swimming.

Anita Gould/Flickr

The St. Croix Boom Site in particular has much to see and do. A picnic area above the river makes it a great place for afternoon stops.

Joe C/Google

A set of stairs leads to the river…

Elkman/Wikimedia Commons

…and when you get to the bottom, you’ll love the scene before you. The beach itself is often used for swimming, sunbathing, and hiking.

Jonni Hahn/Google

But don’t keep your eyes on the water the whole time. The surrounding sandstone cliffs are absolutely beautiful.

nicholas rahm/Google

Over the years, water has carved out many nooks and crannies along the cliffs.

Rene Spranger/Google

An aboveground cave is probably the most fascinating formation. You can easily access it from shore with no climbing or crawling involved.

Dorian Warner/Google

Inside, there are few features. Both painted and carved graffiti mark the walls.

Greig Ballantine/Google

Mostly, this aboveground cave is interesting because few know about it. It may not be as grand as some, but its natural surroundings are downright beautiful.

Michael Goff/Google

Ever been to the aboveground cave at the St. Croix Boom Site? Know of any other secret caves in Minnesota? Let us know in the comments below!

McGhiever/Wikimedia Commons

RTCA NPS/Flickr

Anita Gould/Flickr

Joe C/Google

Elkman/Wikimedia Commons

Jonni Hahn/Google

nicholas rahm/Google

Rene Spranger/Google

Dorian Warner/Google

Greig Ballantine/Google

Michael Goff/Google

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